Okasha, Samir, editor
Oxford University Press, 2016
Buku Teks
Christian, James L. , author
Wadsworth and Cengage Learning, 2012
Buku Teks
Horner, Chris, author
Cambridge, 2004
Buku Teks
Halverson, william H
Random House, 1969
Buku Teks
Losee, John, author
Oxford University Press, 1980
Buku Teks