Myers, Alec Reginald
Penguin Books, 1952
Buku Teks
Doorn, Jacques van
Faculty of Social Sciences, Erasmus University Rotterdam, 1983
Buku Teks
Cheun, Sang Buom
Pan Korean Book Corporation, 1975
Buku Teks
Cornel University Press, 1993
Buku Teks
edited, Frank J. Schwartz, Susan J. Pharr
Cambridge University Press , 2003
Buku Teks SO