Baron, Robert A., author
Allyn and Bacon, 2000
Buku Teks
Baron, Robert A., author
Heights Allyn and Bacon , 1991
Buku Teks
Mercer, Charles, author
Penguin Books, 1975
Buku Teks
DeLamater, John D., author
Colorado Westview Press, 2014
Buku Teks
Pines, Ayala, author
McGraw-Hill, 1993
Buku Teks