Friedmann, Wolfgang, 1907-1972
Penguin Books, 1972
Buku Teks
Bell, Robert R.
Prentice Hall Inc., 1966
Buku Teks
edited by Hendry W. Ehrmann
Vakils, Fiffer and Simons, 1963
Buku Teks
Ewha Women University Press, 2005
Buku Teks
Sanders, Donald H.
McGraw-Hill , 1974
Buku Teks