editor, Joseph F. Littell
McDougal, Littel and Company, 1976
Buku Teks
Gamble, Michael W., author
McGraw Hall, 1986
Buku Teks
Katz, Elihu, author
Free Press, 1964
Buku Teks
[compiled by] Warren K. Agee, Phillip H. Ault, Edwin Emery
Harper & Row Publishers, 1986
Buku Teks
Zuckman, Harvey L., author
West Publishing, 1983
Buku Teks