Tavistock Publications, 1970
Buku Teks
Herskovits, Melville J. (Melville Jean), 1895-1963, author
WW Norton, [Date of publication not identified]
Buku Teks
Gabel, Creighton
Holt, Rinehart and Winston, 1967
Buku Teks
Clammer, J.R.
St. Martin's Press , 1985
Buku Teks
Ember, Carol R., author
Prentice-Hall, 1985
Buku Teks