Osbeck, Mark K., author
Thomson/West, 2010
Buku Teks
Harris, Myra A., author
Prentice-Hall, 1997
Buku Teks
Bander, Edward J., author
Balinger, 1978
Buku Teks
Cohen, Morris L., author
West Publishing, 1968
Buku Teks
Price, Miles O. (Miles Oscar), 1890-1968, author
Brown and Company, 1979
Buku Referensi