Winship, Peter, author
St.paul Minn, 2000
Buku Teks
Spanogle, John A., author
St. Paul Minn, 2000
Buku Teks
Guruswamy, Laskshman, author
[Publisher not identified], 1994
Buku Teks
Folsom, Ralph Haughwout, author
West Group, 1999
Buku Teks
McDougal, Myres S. (Myres Smith), 1906-1998, author
Yale University Press, 1960
Buku Teks