Fenner, M. Kathleen
D. Van Nostrand Comp., 1980
Buku Teks
Kaplin, William A.
Jossey-Bass Publishers, 1980
Buku Teks
Alexander, Rudolph, author
Thomson Brooks/Cole, 2003
Buku Teks
West Publishing Company, 1993
Buku Teks
Ross, Martin J., author
A Fawcett Crest Book, 1967
Buku Teks