Bramer, George R.
Charles E. Merrill Publishing Company, 1981
Buku Teks
Trimmer, Joseph F.
Houghton Mifflin , 1995
Buku Teks
Goldman, Stephen H.
Houghton Miffiln, 1986
Buku Teks
McGraw-Hill, 1990
Buku Teks
edited by J. Karl Nicholas and James R. Nicholl
Allyn and Bacon , 1994
Buku Teks