Hostname: page-component-5c6d5d7d68-7tdvq Total loading time: 0 Render date: 2024-08-09T03:58:05.214Z Has data issue: false hasContentIssue false

The Contents and Terminology of the Mawangdui Texts on the Arts of the Bedchamber

Published online by Cambridge University Press:  26 March 2015

Li Ling
Affiliation:
Department of Chinese, Peking University, Beijing, China P.R.C.
Keith McMahon
Affiliation:
East Asian Languages and Cultures, University of Kansas, Lawrence, KS 66045

Abstract

In the Han, the art of the bedchamber belonged to the disciplines called “prescriptions and techniques,” which also included various medical arts such as nutrition, internal conduction, and associated incantations and spells. This essay investigates the Mawangdui art of the bedchamber texts with special emphasis on their terminology, and briefly addresses the importance of these texts in studying ancient Chinese culture.

Seven texts are examined: “Prescriptions for nourishing life,” “Prescriptions for miscellaneous cures,” “Book of childbirth,” “Ten questions,” ’Joining yin and yang” “Prescriptions for miscellaneous spells,” and “Talks on the loftiest ways under heaven.” The terminology found in these works is organized into the following categories: male and female genitals, the steps of foreplay, positions and methods of intercourse, the benefits and harms of intercourse, techniques of ejaculation control, and male and female sexual reactions. The terminology and topical categories of later bedchamber texts are highly consistent with the Mawangdui texts, especially regarding the following three most influential concepts: “the method of nine shallow and one deep,” “ride many young women, but ejaculate rarely,” and “returning jing to supplement the brain.”

在中國古代歷史文化的發展中, 房中術是一個涉及技術史, 思想史和社會史的復雜問題. 過去, 中國學者葉德輝曾搜集整理過這方面的资料, 荷籣漢學家髙羅佩也做過綜合硏究, 但他們都未能見到 70 年代出土的馬王堆三號漢墓中出土的現存年代最早的房中文獻.

通過對這批房中文獻的硏究, 以及將牠們與晚期資料做對比, 作者論證, 中國古代房中術從術語系統到技術要領(如” 九淺一深之法”, “還精補腦之術” 和” 多御少女而莫數寫精” ) 是一種非常連貫的, 從兩千多年前一直到明代很少改變的傳統.

Type
Articles
Copyright
Copyright © Society for the Study of Early China 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. See the “Yiwen zhi“ 藝文志section of the Hanshu 漢書 (Beijing: Zhonghua shuju, 1962), 30.17761780 Google Scholar.

2. See Shiji (Beijing: Zhonghua shuju, 1959), 105.2796 Google Scholar.

3. See Hanshu, 30.1778 Google Scholar.

4. For the Shiwen 十問, see Mawangdui Hanmu boshu 馬王堆漢墓帛書׳ vol. 4 (Beijing: Wenwu chubanshe, 1985), 146, no. 19, and 152, no. 97Google Scholar.

5. Baopuzi neipian jiaoshi 抱樸子內篇校釋, ed. Ming, Wang 王明 (Beijing: Zhong-hua shuju, 1985), 150 Google Scholar.

6. See Baopuzi neipian jiaoshi, 133; and Guofu, Chen 陳國符, Daozang yuanliu kao 道藏源流考 (Beijing: Zhonghua shuju, 1963), 365369 Google Scholar. The Chen Shejing 陳赦經and the Tianmenzi jing 天門子經 mentioned in the Baopuzi are also bedchamber art texts.

7. See Dehui, Ye 葉德輝, Xinkan Sunü jing xu 新刊素女經序, in Shuangmei jing'an congshu 雙梅景闇截書 (Changsha: Yeshi Xiyuan kanben, n. d.)Google Scholar; and van Gulik, Robert, Sexual Life in Ancient China (Leiden: Brill, 1974), 121160 Google Scholar.

8. A work with “Rongcheng“ in the title existed in the Western Han and its skills were transmitted in the late Eastern Han by Leng (or Ling) Shouguang 冷/靈壽 光, Gan Shi 甘始, Dongguo Yannian 東郭延年, and Feng Heng 封衡 (i.e., Feng Junda 封君達, the “Blue Ox Daoist “靑牛道士); see Hanshu, 30.1778 Google Scholar; Hou Hanshu (Beijing: Zhonghua shuju, 1965), 72.2750 Google Scholar; Shenxian zhuan 神仙傳 (Siku quanshu ed.), 7.291 ab, and 10.311aGoogle Scholar; Bowu zhi jiaozheng 博物志校正, ed., Ning, Fan (Beijing: Zhonghua shuju, 1980), 5.61 Google Scholar. Works taking the names of Sunü, Xuannü, and Pengzu can be found in the Han, Western Liexian zhuan 歹仙傳 (Siku cfuanshu ed.), 1.492b and 2.505b Google Scholar. For Zidu (i.e., Wu Yan 巫炎), see the Han, Eastern Fengsu tongyi 風俗通義 fragments in Fengsu tongyi jiaoshi 風俗通義校釋, ed., Shuping, Wu 吳樹平 (Tianjin: Renmin chubanshe, 1980), 466 Google Scholar.

9. E.g., there are bedchamber texts of Yanzi 郯子, Geshi 葛氏, and Xu Taishan 徐太山 (Xu Wenbo 徐文伯); see Suishu (Beijing: Zhonghua, 1973), 34.1037, 1040–50Google Scholar; Jiu Tangshu (Beijing: Zhonghua, 1975), 47.2047–51Google Scholar; Xin Tangshu (Beijing: Zhonghua, 1975), 59.1566–73Google Scholar. The Japanese catalogue Nihon koku genzai shomoku 日本國見在書目 of the Kampyo era (889–897) lists two such works, both referring to Sunü, 37b and 41a; in Guyi congshu 古逸叢化 ed. Shuchang, Li昌 (Tokyo, n.d.), no. 19Google Scholar.

10. See Yimou, Zhou 周一謀, Zhongguo gudai fangshi yangsheng xue 中國古代房事養生學 (Beijing: Zhongwai wenhua chuban gongsi, 1989), parts four and fiveGoogle Scholar.

11. See Yi xin fang 醫心方 (Beijing: Renmin weisheng chubanshe, 1955)Google Scholar. References to this text will be to the Fangnei section unless otherwise indicated.

12. van Gulik, R.H., Erotic Colour Prints of the Ming Period (Tokyo: 1951), vol. 2 Google Scholar.

13. As Li Ling's forthcoming edition will show, the Fangnei consists of a total of thirty-eight excerpts from twenty-three works.

14. See his Shuangmei jing'an congshu, mentioned above, n. 7.

15. For example, he took the Sunü jing, Xuannü jing, and Pengzu jing as one work consisting of questions and answers between Huangdi and Sunü, Xuannü, and Cainü 采女. The Sunü jing is, in fact, a series of questions and answers between Huangdi and Sunü; the Xuannü jing between Huangdi and Xuannü; and the Pengzu jing between Pengzu and Cainü; the three are distinct works. In addition, he failed to see that the Yufang mijue was an independent compilation of separate works. Instead, he took all of the Sunü jing excerpts and all of the Pengzu jing excerpts concerning Cainü and put them into his version of the Sunü jing. In addition, his version of the Yufang mijue left out the one excerpt in the Fangnei from the Zidu jing. Finally, his editions drew on only five sources (for a total of 90 excerpts) of the 23 sources (138 excerpts) that are actually included in the Fangnei. In addition, his Xuannü jing and Yufang mijue left out portions that are excerpted in other parts of the Yi xin fang. He also made many errors of transcription.

16. van Gulik, R.H., Sexual Life in Ancient China (Leiden: E.J. Brill, 1961)Google Scholar.

17. See Changsha Mawangdui sanhao Hanmu zhujian Yangsheng fang shiwen“ 長沙馬王堆三號漢墓竹簡養生方釋文, in Mawangdui yishu yanjiu zhuankan 馬王堆醫書硏究專刊 2 (1981), 214 Google Scholar.

18. In 1987, Xigui, Qiu 裘錫圭corrected a number of mistakes in the earlier works in his “Mawangdui sanhao Hanmu Yangsheng fang jianwen shi du suoyi“ 馬王堆三號漢墓養生方簡文釋讀瑣議, Hunan kaogu jikan 湖南考古輯刊 4, 132136 Google Scholar. In addition, Japanese scholars have made contributions, as found in Shin hatsugen Chūgoku kagakushi shiryo no kenkyū 新發現中國科學史資料の硏究, ed. Keiji, Yamada 山田慶兒 (Kyoto: Kyoto Daigaku jimbun kagaku kenkyüjo, 1987)Google Scholar, which is a commentary and Japanese translation of the second Chinese interpretive edition. This work exhibits great effort in the examination of lexical problems, but suffers in some instances because of mistakes in the Chinese interpretations it follows.

19. Mawangdui Hanmu boshu, vol. 4 (Beijing: Wenwu chubanshe, 1985)Google Scholar.

20. For example, in 1987 Qiu Xigui pointed out several errors, one of the most important of which concerns a line missed in the copying of the Yangsheng fang (located between lines 215 and 216); see Mawangdui yishu shi du suoyi“ 馬王堆醫書釋讚瑣 議, Hunan zhongyi xueyuan xuebao 湖南中醫學院學報4 (1987), 4244 Google Scholar. See, also, the Research Group on Mawangdui Medical Texts of the Hunan Institute of Chinese Medicine, Mawangdui yishu kaozhu 馬王堆醫書考注 (Tianjin: Tianjin kexue jishu chubanshe, 1988)Google Scholar; and Harper, Donald, “The Sexual Arts of Ancient China as Described in a Manuscript of the Second Century B.C.,“ Harvard Journal of Asiatic Studies 47.2 (1987), 539593 CrossRefGoogle Scholar, which is a discussion of the He yinyang.

21. See Mawangdui Hanmu boshu, 97–120.

22. The Mawangdui yishu kaozhu distinguishes seven sections and puts weili 爲醴 into “Prescriptions for curing impotence,“ bian jin nei 便近內and X jin □巾 into “General prescriptions for strengthening yangyongshao 用少 into “General prescriptions for tonic supplement,“ X yu □語and shiyin 食引 into “Prescriptions for tonic supplement in the bedchamber.” In addition, it takes hing zui zhong 病最腫 as a male illness. All of these are debatable.

23. See Mawangdui Hanmu boshu, 99 nos. 1–10; hereafter, numbers will be given in the text.

24. In Fangnei (46b), this prescription is found under “Prescriptions for increasing the size of the yin,” which includes cures for “smallness of the jade stalk.”

25. See Sunü fang (Ye Dehui edition), 3a, which calls it jing shao 精少.

26. See Fangnei, 47a–b, which gives two prescriptions: “making the jade gate smaller“ and “making the vagina tight, small, and hot,“ both of which are for curing “largeness of the jade gate”.

27. See Huainan wanbi shu 淮南萬畢術and Bowu zhi 博物志, in Taipingyulan 太平御覽 (Beijing: Zhonghua shuju, 1960), 776.3266 and 946.4200Google Scholar. Yi xin fang, 26.19b Google Scholar, quotes the “Ling qi fang “靈奇力, calling this the “art of testing lasciviousness.”

28. The term jin nei also occurs in Wushier bingfang 五十二病方; see Mawangdui Hanmu boshu, 29, no. 28. For this use of nei to refer to woman, also see Shiji, 105.2797, 2799, and 2801 Google Scholar: “The illness is due to drinking alchohol and playing with women”; “The illness is due to playing with women”; “The illness is due to excess anger and conjoining with women.”

29.X” stands for a missing character(s) in the original text, a convention we will follow hereafter.

30. See Aichun, Guo 郭露春, Huangdi neijingsuwen jiaozhu yuyi 黃帝內經素問校注語釋 (Tianjin: Kexue jishu chubanshe, 1981), 471 Google Scholar, which contains the words “heaven and earth join qi“ (tiandi he qi 天地合氣). The art of the bedchamber compares intercourse between man and woman to the joining of qi between heaven and earth, referring to intercourse by the words he qi. The Tang work Guang Hongming ji 廣宏明集 quotes the Huang shu of the Tianshidao 天師道 cult of the late Eastern Han as containing the expression “join qi and absolve guilt“ (he cji shi zui 合氣釋罪), which originates from the art of the bechamber; see Guang Hongming ji (Sibu congkan ed.), 8.19b Google Scholar. This reference can also be found in van Gulik, , Sexual Life in Ancient China, 8889 Google Scholar.

31. See Mawangdui Hanmu boshu, 121–30.

32. The Pengzu jing perhaps refers to such an aphrodisiac: “Some put a medicinal powder into the vagina, some carve a penis out of an ivory tusk and use that, but both of these methods harm the life-span and cause the user to sicken and die before her time”; see Fangnei, 36a. Mawangdui yishu kaozhu correctly concludes that neijia is used with men, yue with women, but fails to see jia as a prescription for increasing the size of the penis and yue as a prescription for tightening the vagina. It also fails to give a correct interpretation of zhongshen, zhongshen kong, and qian; see 315 n. 1, 316 n. 8, 318 n. 3.

33. See Mawangdui Hanmu boshu, 131–142.

34. See Mawangdui Hanmu boshu, 143–152.

35. This is also called fu qi 月艮氣 or tiao qi 調氣, and is now generally called qigong 氣功.

36. Mawangdui Hanmu boshu, 153–6.

37. Cao 操 also occurs as 搔 (see the “Chongshi “蟲触 section of the Wushier bing-fang); it and dun 搪both mean to caress.

38. Xu 陶, originally meaning to open the mouth and exhale, here means to kiss. The ancient art of the bedchamber emphasizes inhaling the woman's breath and sucking in her saliva, both of which were done through kissing.

39. Yi xin fang, 26.17b21a Google Scholar, contains similar prescriptions. According to Xigui, Qiu, “Mawangdui sanhao Hanmu,“ 133 Google Scholar, the wei 微 of the bamboo manuscripts should be read as mei 媚.

40. See Jiaben, Shen 沈家本, Lidai xingfa kao 歷代刑法考 (Beijing: Zhonghua shuju, 1985), 14311432 Google Scholar.

41. See Shanhai jing jiaozhu 山海經校注, ed. Ke, Yuan 袁珂 (Shanghai: Guji chubanshe, 1980), 142 Google Scholar.

42. Mawangdui Hanmu boshu, 161–167.

43. See also the similar idea expressed in Shiwen 5, 148 n. 43.

44. Mawangdui Hanmu boshu, 107, no. 83; the words signifying “to wipe “are cao 操, dun 搪, and min 据 (ί).

45. Mawangdui yishu kaozhu takes ma 馬 to be the same in meaning as the ma of the colloquial usage pao ma 跑馬; i.e., “to ejaculate,“ ma here meaning penis (282, n. 14). The “Weizhi“ 微旨 chapter of the Baopuzi refers to a method of halting ejaculation, referred to as zou ma 走馬, used to supplement the brain; the expression comes from the Lflozi; see Baopuzi, 129; and Laozi (Zhuzi jicheng edition), 28. However, there is no evidence that ma means penis. The second part of the “X jin “says: “Wipe the vagina with a [medically dipped] cloth and the horse will then be aroused”; here ma refers to vagina.

46. This term occurs in the “Jiudi“ 九地section of the Sunzi 孫子, where it can mean either parts of the body between the head and feet, or the genitals; see Shiyijia zhu Sunzi, 十ㄧ家注孫子 (Shanghai: Zhonghua shuju, 1962), 3.197 Google Scholar. The term neishen 內身of Ming fiction also carries this meaning.

47. See 316, n. 8, and 318, n. 3.

48. In Mawangdui Hanmu boshu, this graph is transcribed as 囊. The transcription given here is that of Xigui, Qiu, “Mawangdui yishu shi du suoyi,“ 44 Google Scholar.

49. This is different from the term “jade nectar,“ yujiang 玉娥, of the Yi xin fang, which refers to saliva; see Fangnei, 7a.

50. See Mishu shizhong, 125, in van Gulick, , Erotic Colour Prints, vol. 2 Google Scholar.

51. Of the other terms besides these nine, e.g., guhu (lanhu), zhuogua, jengji, fanqu, heyu, chilu, etc., all are unidentifiable except for fengji, which from a passage in Tianxia zhi dao tan 20, 166, nos. 63–64, seems to refer to the labia. Mawangdui yishu kaozhu (438, n. 16) also takes fengji as labia.

52. See, for example, the “Zhuyan“ (主言) section of Da Dai liji jiegu 大戴禮記解詁, ed., Pinzhen, Wang 王聘珍 (Beijing: Zhonghua shuju, 1983), 1.5 Google Scholar.

53. See Nan jing jiaoshi 難經校釋, ed., xueyuan, Nanjing zhongyi (Beijing: Renmin weisheng chubanshe, 1979), 45 Google Scholar.

54. Mishu shizhong, 125.

55. Zhushi is only found in the Xuannü jing; Fangnei, 10b.

56. The major source for these terms is Fangnei; for danxue and yangtai, see 11a and 17a; for shentian and yougu, see 11a and 18b; for xuanpu and tianting, 18b; for biyong 11a; and for jin'gou, yuli and mitai, lia and 18b.

57. His Erotic Colour Prints of the Ming Period provides an appendix on the terminology of the art of the bedchamber. He believed correctly that yumen is the vagina, biyong (which he translates as “Examination Hall”) is the major labia, and yuli is the lower bridge between the minor labia, and was more or less correct in believing that maichi is the orifice of the vagina, yougu the womb, and danxue the vaginal passage. But he erred in stating that mitai refers to the major labia and that jin'gou is the clitoris. He corrected these errors in his later Sexual Life in Ancient China after having consulted the Eisei-hiyosho, stating that ruitai is the clitoris and jin'gou the bridge between the upper part of the minor labia (see p. 127n).

58. See Jianchun, Yi 易建純, “ Tianxia zhidao tan: ‘Qisun,’ ‘Bayi’ zhushi“ 天下至道談七損八益注釋, Mawangdui yishu zhuankan 馬王堆醫書專刊 1 (1981), 2732 Google Scholar; see, e.g., p. 28, which quotes Wang Bing's 王冰 notes to the Suwen to interpret yong as referring to intercourse.

59. See He yinyang 155, nos. 116–7; Tianxia zhidao tan, 165, nos. 42–3; and Yangsheng fang X, 116–7, no. 201.

60. See the “Jingshen“ 精神 chapter of the Huainanzi 淮南子 (jicheng, Zhuzi ed.), 105 Google Scholar; and the “Zaying“ 雜應 chapter of the Baopuzi, which refers to numerous types of exercises for internal conduction, including yuanju 援據 and tu jing 兔驚 (jing is an error for wu 騖); Baopuzi, 274.

61. See He yinyang 4, 156, nos. 118–119 (shixiu), from which the following terms are taken; Yangsheng fang, section X, 117, no. 202; and Tianxia zhi dao tan 12, 165, no. 46 (badao).

62. Dongxuanzi treats these topics under “Nine Forms“ (jiu zhuang 九狀), and “Six Positions“ (liu shi 六勢); 18a-b.

63. See Yangsheng fang, section X, 117, nos. 203–204, and Tianxia zhi dao tan 11, 165, no. 45 (note that this is not the same shixiu as in the He yinyang).

64. See section 5, “Eight Benefits“ (164, no. 31) and section 7, “Governing the Eight Benefits,“ (164–165, nos. 33–36), from the latter of which the following explanations are derived.

65. These first two are similar to the first two of the “Eight Benefits” of the Sunü jing (19a–20a), which are otherwise quite different from the Mawangdui texts.

66. See Fangnei, 20a–21b.

67. See Mishu shizhong, 128–9.

68. See the “Nine Movements“ section of Shiwen 3, 146, nos. 19–22, the “Ten Movements“ section of He yinyang 2, 155, nos. 112–115, and the “Ten Movements” section of Tianxia zhi dao tan 3, 163, nos. 22–24. See also below on the technique of “returning jing to supplement the brain.”

69. See also Tianxia zhi dao tan 2, 163, nos. 15–16 (sanyi), and 18, 166, no. 56 (sanzhi).

70. See also Tianxia zhi dao tan 17, 166, nos. 54–55, under wuzheng and wuyu. Later equivalents of these five can be found in Sunü jing (12b) under wuzheng zhi hou 五徵之候, “Indications of the Five Signs,“ and Sunü miaolun (127–8) under wuyu zhi hou 五欲之候, “Indications of the Five Desires”.

71. See also Yangsheng fang, section X (117, no. 203), and Tianxia zhi dao tan 14 (165, no. 49) and 16 (166, nos. 51–53) under badong and baguan. These eight correspond to eight of the “Ten Movements “(shidong) of Sunü jing (13a-b), though not in the same sequence except for 1, 2, and 6. No. 3 of He yinyang corresponds to no. 5 of Sunü jing, 4 to 7, 5 to 8, 7 to 3, and 8 to 4.

72. On the “Five Sounds,” see also Yangsheng fang, section X (117, no. 203), and He yinyang 6 (156, nos. 115–116).

73. See also Tianxia zhi dao tan 18 (166, nos. 56–58) under shiyi.

74. The “Yigan” 益甘 section of Yangsheng fang uses gan with the same meaning (104).

75. See Sunü jing in Fangnei, 19a-20a; Xuannü jing, in Fangnei, 14b-16a; and Sunü miaolun in Mishu shizhong, 138–139.

76. See Fangnei, “Haonü” and “Enü,” 33a-35a.

77. See Fangnei, “Shixie,“ 23b-24b.

78. See Dunhuang MS S 6825, and Zongyi, Rao 饒宗頓, Laozi xianger zhu jiao jian 老子想爾注校箋 (Hong Kong: Tong Nam Publishers, 1956)Google Scholar. Also see Boltz, William, The Religious and Philosophical Significance of the Hsiang-er Lao tzu in the Light of the Ma-wang-tui Silk Manuscripts,“ Bulletin of the School of Oriental and African Studies, 45.1 (1982), 95117 CrossRefGoogle Scholar.

79. See Guofu, Chen 陳國符, Daozang yuanliu kao 道藏源流考 (Beijing: Zhonghua shuju, 1963), 366367 Google Scholar.

80. In an appendix to Sexual Life in Ancient China (pp. 339–359), van Gulik speculates that the Chinese sexual arts were earlier than the Tan tri c ones in India and that the Tan tri c were influenced by the Chinese in the Tang, after which the Tantric arts then returned to influence the Chinese.

81. See zhenglizu, Zhangjia shan Hanjian, “Zhangjia shan Hanjian Yinshu shi wen“ 張家山漢簡《引書〉釋文, Wenwu 1990.10, 8286 Google Scholar. In the Mawangdui texts, see: Yangsheng fang 118, nos. 218–219; Shiwen 148, nos. 45–46, nos. 48–51, 149, nos. 62–64, and 150, nos. 71–72; and Tianxia zhi dao tan 164, 33.

82. See, for example, the Xian jing in Yixin fang, 22b.

83. See Fangnei, “Jinji“ 禁忌, 35a-38b.

84. See the Yiwen zhi“in the Hanshu, 30.1779 Google Scholar (the preface to the Fangzhong “房中 section) and the “Qiuzi“ 求子 section of the Fangnei, 28a-33a.

85. See Wang Bi, Laozi zhu (Zhuzi jicheng ed.), 1 (ch. 1) and 4 (ch. 6).

86. Bi, Wang, Laozi zhu, 33 (ch. 55)Google Scholar.

87. See Mawangdui Laozi, (Beijing: Wenwu chubanshe, 1976), 42 (text B)Google Scholar.

88. The Laozi xianger zhu is said by some to be by Zhang Ling, by others by Zhang Lu. It is probably the case that it was formulated by Ling and propagated by Lu; at any rate, it represents one school of thought. In the Shenxian zhuan 神仙傳, the biography of Zhang Daoling says: In curing illnesses, he used methods taken from the books of Xuannü and Sunü but made slight changes; the essence was still the same”; (Siku quanshu ed.), 5.282 Google Scholar. The Laozi xianger zhu says: “The true Way is to teach people how to transform jing into shen. The false Way that is popular in recent times is travesty and quackery. The propagators of this false Way purport to be teaching the works of Huangdi, Xuannü, Gongzi, and Rongcheng Gong. Although they attempt to withhold ejaculation during intercourse and to return the jing to supplement the brain, they are unable to concentrate their energy and completely fail to attain their goal”; see Zongyi, Rao, Laozi xianger zhu jiao jian, 12, 38 Google Scholar. From this it seems that, although Zhang Ling based himself on Rongcheng, Xuannü, and Sunü, he was considered to be separate from the other schools popular in his time.

89. The Huang shu is also by Zhang Ling. See Zongyi, Rao, Laozi xianger zhu jiaojian, 104–5Google Scholar.

90. See Hou Hanshu, 72.2703–51Google Scholar, and Bowu zhi jiaozheng, 61–5Google Scholar.