Ides, Allan
Aspen Law & Business, 2003
Buku Teks
Marks, R. J. (Raymond John)
Pergamon Press, 1985
Buku Teks
Wenger, Leopold
Veritas press, 1940
Buku Teks
James, Fleming
Little, Brown and Company, 1977
Buku Teks
Blume, William Wirt
Prentice-Hall, 1955
Buku Teks