Edited sentence: (1983), China among equals, University of California Press, pp.(1984) A new history of Korea, p.100 - 101.125, Harvard University Press, ISBN 067461576X.154 - 157, ISBN 0520045629.171 - 174, ISBN 0231105673.57, Greenwood Publishing Group, ISBN 0313332967.; William Theodore De Bary, (2000), Sources of Korean Tradition: From early times through the sixteenth century, Columbia University Press, pp.Kang, Jae-eun; Lee, Suzanne.Kim, Chun-gil, (2005), The history of Korea, p.Lee, Ki-baek; Wagner, Edward W.Lee, Peter H.Rossabi, Morris.The land of scholars pp