Westview Press, 1984
Buku Teks
Boston [etc.] DC Heath and Company 1050
Buku Teks
Short, Ema, author
Cambridge University Press, 2013
Buku Teks
Vleeskruyer, Rudolf
Amsterdam North-Holland Publishing 1953
Buku Teks
Montreal, Canada The Reader's Digest Association 1968,
Buku Teks