Thompson, William Fletcher, 1929-, author
Louisiana State University Pres, 1994
Buku Teks
Col, Arthur Charles, 1886-
Mich., Scholarly Press, 1934
Buku Teks
Bryan, J.
McGraw-Hill Book Company, Inc., 1960
Buku Teks
Avon Book Division, 1961
Buku Teks
Ketchum, Richard M., author
American Heritage Publishing, 1960
Buku Teks