Kaplan, Howard B., author
Sage Publications, 1984
Buku Teks
Terrance M. Brungardt
Houghton Miffiln, 1983
Buku Teks
Yablonsky, Lewis, author
Wadsworth, 2000
Buku Teks
Trojanowicz, Robert C., 1941-, author
Prentice-Hall, 1987
Buku Teks
Arnold, William R., author
Houghton Mifflin, 1983
Buku Teks