* Joseph Needham; Tsien Tsuen-Hsuin (11 de julio de 1985). Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology, Part 1, Paper and Printing. Cambridge University Press. p. 234
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* Woods, Michael; Woods, Mary (2000). Ancient Communication: Form Grunts to Graffiti.pp 51–52. Minneapolis: Runestone Press; an imprint of Lerner Publishing Group
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* Yuuko Suzuki, Introduction to Japanese calligraphy, Search Press 2005, Calligraphie japonaise, 2003, éd. Fleurus, Paris
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== Bibliografia ==
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* Koops, Matthias. Historical Account of the Substances Which Have Been Used to Describe Events, and to Convey Ideas, from the Earliest Date, to the Invention of Paper. ISBN 978-11-0800-904-1
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* Needham, Joseph; Tsuen-Hsuin, Tsien (11 de julio de 1985). Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology, Part 1, Paper and Printing (en inglés). Cambridge University Press. p. 5.
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* Ramos-Sánchez, MC; Martín-Gil, FJ; José-Yacamán, M. (2006). «Chemical composition of a fountain pen ink». Journal of Chemical Education (83): 1476-78