Ballast, David Kent
Professional Publications, 2002
Buku Teks
Ohara, Steven E.
Professional Publications, 2002
Buku Teks
Conn, Steven
University of Pennsylvania Press, 2003
Buku Teks
Harris, Cyril M.
W.W. Norton, 1998
Buku Referensi
Andrews, Wayne
Macmillan, 1978
Buku Teks