Jelliffe, Derrick B., author
Office of War on Hunger Agency for International Development , 1969
Buku Teks
edited by Mildred Kaufman
An Aspen Publication, 1990
Buku Referensi
Bee, Helen L., author
Allyn and Bacon, 2010
Buku Teks
King, Felicity Savage, author
Oxford University Press, 1995
Buku Teks
Holden, Chris
Bailliere Tindall , 2000
Buku Teks