Brewster, Lawrence G., author
St. Martin`s Press, 1982
Buku Teks
Brewster, Lawrence G., author
Thomson wadsworth, 2004
Buku Teks
Judd, Dennis R., author
Little, Brown, 1979
Buku Teks
Huntington, Samuel P., author
The Belknap Press, 1981
Buku Teks
McCarthy, Eugene J.
Macmillan, 1962
Buku Teks