edited by Miyoung Pyo
RHED Publishing , 2013
Buku Referensi
Koningsveld, R., author
Oxrord University Press, 2008
Buku Teks
Yu, Yan, author
Intercontinental Press, 2008
Buku Teks
Bilenky, S.M., author
Pergamon Press, 1974
Buku Teks
Douglas-Young, John, author
Parker Publishing Company, 1979
Buku Referensi