Welch, Jack, author
Warner Books, 2001
Buku Teks
Slater, Robert, author
McGraw-Hill, 1999
Buku Teks
edited by G. William Dauphinais and Colin Price
Simon & Schuster , 1998
Buku Teks
Greenwood, Ronald G., author
Lexinton Books, 1974
Buku Teks
Fenno, Richard F.
Harvard University Press, 1959
Buku Teks