Bartholomew, David J., author
John Wiley & Sons, 1981
Buku Teks
Boulding, Kenneth E. (Kenneth Ewart), 1910-1993, author
Fefer and Simons , 1966
Buku Teks
Organisation for Economic Cooperation and Development , 1966
Buku Teks
Prentice-Hall, 1970
Buku Teks
edited by Norman MacKenzie
The New American Library, 1968
Buku Teks