Herring, E. Pendleton, author
Norton, 1966
Buku Teks
Irish, Marian D., author
Prentice-Hall, 1962
Buku Teks
by William J. Keefe ... [and others]
The Dorsey Press, 1983
Buku Teks
McKenna, George, author
McGraw-Hill, 1998
Buku Teks
Dye, Thomas R., author
Harcourt Brace College, 2000
Buku Teks