Havard, William C.
Cowles Book Company,Inc., 1969
Buku Teks
Philip G. Schrag
Little,Brown and Company, 1974
Buku Teks
Yell, Mitchell L.
Prentice-Hall, 1998
Buku Teks
Bracy, Warren D.
The Bobbs-Merrill Company, Inc., 1978
Buku Teks
Indonesia. Departemen Pendidikan dan Kebudayaan
Bp. Dharma Bhakti , 1989
Buku Referensi