Wynar, Bohdan S.
Libraries Unlimited, Inc., 1967
Buku Teks
Frost, Carolyn O., author
Libraries Unlimited, 1989
Buku Teks
McGovern, William M., author
University of North Carolina Press, 1939
Buku Teks
Nazareth, Pascal Alan, author
arvodaya International Trust : Gandhi Centre of Science & Human Values, Bharatiya Vidya Bhavan, 2006
Buku Teks
Ward, Dederick C.
Scarecrow Press, 1981
Buku Referensi