Oxford University Press, 1995
Buku Teks
Cho, Hae-il
Dong-su-Munhak-sa, 1990
Buku Teks
New York: W.W.Norton & Company, 1988,
Buku Referensi
International Society for Educational Information, Inc., 1973
Buku Teks
Zupnick, Elliot
Columbia University Press, 1957
Buku Teks