Bisson, T.A., author
Macmilan Co., 1945
Buku Teks
Wittkopf, Eugene R., author
Thomson, 2002
Buku Teks
Leopold, Richard W., author
Alfred A. Knopf, 1962
Buku Teks
Pratt, Julius W., author
Prentice-Hall, 1965
Buku Teks
Hayes, Margaret Daly, author
Westview Press, 1984
Buku Teks