Allyn and Bacon, 1964
Buku Teks
Risjord, Norman K., author
Prentice-Hall, 1985
Buku Teks
Williams, T. Harry, author
Alfred A. Knopf, 1963
Buku Teks
Beard, Charles A., author
New Home Library, 1944
Buku Teks
Alden, John Richard, author
American Book Company, 1960
Buku Teks