Marr, David, author
Random House, 1991
Buku Teks
Welter, Volker M., author
MIT Press, 2002
Buku Teks
Colmer, John, author
Methuen, 1984
Buku Teks
Kemp, Patrick S.
Dow Jones-Irwin, Inc., 1970
Buku Teks
Patrick, Daniel
Harvard University Press, 1990
Buku Teks