Snyder, Houis L.
Princeton University Press, 1964
Buku Teks
Schapiro, J. Salwyn
McGraw-Hill Book Company, Inc., 1950
Buku Teks
Routledge, 1992
Buku Teks
Mende, Tibor
The Noonday Press, 1953
Buku Teks
Kegley, Charles W. (Charles William), Jr., author
Wardsworth, 2010
Buku Teks