Weinberg, Meyer
Prentice Hall Inc., 1965
Buku Teks
Plamenatz, John
Longman, 1991
Buku Teks
Altschuler, Bruce E.
Prentice-Hall, 1996
Buku Teks
Bell, Robert R., editor
Prentice Hall Inc., 1966
Buku Teks
Friedmann, Wolfgang, 1907-1972
Penguin Books, 1972
Buku Teks