Bill, James A., author
Littel Brown and Company, 1984
Buku Teks
Bill, James A., author
Little, Brown, 1979
Buku Teks
Harari, Maurice, author
Prentice-Hall, 1962
Buku Teks
edited by David N. Balaam and Michael J. Carey
Allanheld, Osmun, 1981
Buku Teks
edited by James Piscatori
Westview Press, 1987
Buku Teks