Lo, A. (). „The game of leaves: An inquiry into the origin of Chinese playing cards”. Bulletin of the School of Oriental and African Studies. 63 (3): 389. doi:10.1017/S0041977X00008466.
J. Brunet i Bellet, Lo joch de naibs, naips o cartas, Barcelona, 1886, quote in the "Diccionari de rims de 1371 : darrerament/per ensajar/de bandejar/los seus guarips/joch de nayps/de nit jugàvem, see also le site trionfi.com
Needham, Joseph and Tsien Tsuen-hsuin. (1985). Science and Civilization in China: Volume 5, Chemistry and Chemical Technology, Part 1, Paper and Printing. Cambridge University Press., reprinted Taipei: Caves Books, Ltd.(1986)