Chafe, William Henry
Oxford University Press, 1995
Buku Teks
Wiebe, Robert H.
Harvart University Press , 1962
Buku Teks
Bailey, Stephen K.
Henry Holt, 1957
Buku Teks
Smith, Hedrick
Ballantine Books, 1988
Buku Teks
Rossiter, Clinton, 1917-1970
Alfred A. Knopf, 1956
Buku Teks