Crawford, William R., author
Frederick A. Praeger, 1961
Buku Teks
Martin, Michael Rheta, author
The Bobbs Merrill, 1968
Buku Referensi
edited by Howard J. Wiarda, Harvey F. Kline
Westview Press, 2007
Buku Teks
Wynia, Gary W., author
Cambridge University Press , 1984
Buku Teks
Wiarda, Howard J., author
Wardword, 1995
Buku Teks