Walker, Edward Everett, 1900-1974
Charles Scribner's Sons, 1943
Buku Teks
edited by Nathan Glick
United Sates Information Agency, 1989
Buku Teks
Holt, Rinehart and Winston, 1961
Buku Teks
Saye, Albert B.
Prentice-Hall, 1966
Buku Teks
Patman, Wright, 1893-1976
Bantam Books, 1957
Buku Teks