Bendix, Reinhard, author
John Wiley & Sons, 1956
Buku Teks
Bendix, Reinhard, author
University of California Press, 1974
Buku Teks
Beach, Dale S., author
Macmillan, 1975
Buku Teks
Hunter, Guy, author
University of London Press, 1961
Buku Teks
Yoder, Dale, author
Prentice-Hall, 1962
Buku Teks