Fawcett Pub, 1956
Buku Teks
Kennedy, William Jerald
West Publishing Company, 1977
Buku Teks
Kennedy, Kett Howard
University of Queenslan Press, 1978
Buku Teks
Kennedy, Mitchell L.
John Wiley & Sons, 1998
Buku Teks
Kennedy, X. J., author
Pearson Longman, 2005
Buku Referensi