Sackheim, George I., author
Macmillan, 1968
Buku Teks
by Horace D. Crockford [and others]
John Wiley & Sons, 1975
Buku Teks
Anderson, Franz E., author
Burgess Publishing, 1979
Buku Teks
Sousa, John J., author
Rhode Island Consortium, 1990
Buku Teks
Gerking, Shelby D., author
Burgess, 1970
Buku Teks