Watson, David L., author
Scott, Foresman, 1984
Buku Teks
DeLamater, John D., author
Colorado Westview Press, 2014
Buku Teks
Pines, Ayala, author
McGraw-Hill, 1993
Buku Teks
Baron, Robert A., author
Heights Allyn and Bacon , 1991
Buku Teks
Taylor, Shelley E., author
Prentice-Hall, 1997
Buku Teks