Angle, Stephen C., author
Camberidge University Press , 2002
Buku Teks
Park, Hyunhee, author
Cambridge University Press, 2012
eBooks
Segall, Marshall H., author
Brooks/Cole Publishing, 1979
Buku Teks
Australia Goverment Publishing Service, 1995
Buku Teks
Pergamon Press, 1990
Buku Teks