Spulber, Nicolas
Indiana Univeristy Press , 1965
Buku Teks
Schapiro, Leonard editor
Fredrick A. Praeger, 1963
Buku Teks
Sanchez-Sibony, Oscar, author
Cambridge University Press, 2014
Buku Teks
edited by Morris Bornstein, Daniel R. Fusfeld
Richard D. Irwin, 1966
Buku Teks
Hopper, Bruce
Houghton Miffiln, 1931
Buku Teks