Roussopulos, Dimitrios I
Black Rose Books, 1975
Buku Teks
edited by Gerald Zaltman, Philip Kotler, Ira Kaufman
Holt, Rinehart and Winston, 1972
Buku Teks
Barnett, Homer Garner, author
McGraw-Hill, 1953
Buku Teks
edited by S.N. Eisenstadt
Little, Brown and Company, 1968
Buku Teks
McRobert, Kenneth
McClelland and stewart, 1976
Buku Teks