Williamson, J. Peter (John Peter), author
Scott, Foresman, 1968
Buku Teks
Schlesinger, Rudolf B.
The Foundation Press, 1950
Buku Teks
Kauper, Paul G., author
Little, Brown, 1971
Buku Teks
Hamilton, Robert W.
St. Paul, Minn, 1989
Buku Teks
Dine, Janet, author
Blackstone Press, 1993
Buku Teks