Martín i Roig, G. (2005). Line and shading in drawing (1st U.S. ed.). Barron's Educational Series.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रMartín i Roig, Gabriel. Line and Shading in Drawing. 1st U.S. ed. Hauppauge, NY: Barron's Educational Series, 2005.
एमएलए (8वां संस्करण) प्रशस्ति पत्रMartín i Roig, Gabriel. Line and Shading in Drawing. 1st U.S. ed. Barron's Educational Series, 2005.
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