West Publishing Company, 1993
Buku Teks
Ross, Martin J.
A Fawcett Crest Book, 1967
Buku Teks
Ratliff, Richard C.
The Scarecrow Press,Inc., 1972
Buku Teks
Clark, Lawrence S.
McGraw-Hill, 1988.
Buku Teks
Rodgers, William H.
[Publisher not identified], 1977
Buku Teks