edited by Ralph Cohen
Sheridan Press, 1989
Buku Referensi
Newton, K.M.
Harvester Wheatsheaf , 1990
Buku Teks
California : Stanford University Press
Majalah, Jurnal, Buletin
edited by Ralph Cohen
Johns Hopkins University Press, 1974
Buku Teks
Juhl, P.D.
Princeton University Press, 1980
Buku Teks