Tag, Nancy R., author
Sage, 2012
Buku Teks
Lewis, Herschell Gordon, author
Prentice-Hall, 1986
Buku Teks
Schwab, Victor O
Wilshire Book Company, 1962
Buku Teks
Greenberg, Miriam, author
Routledge, 2008
Buku Teks
Garbett, Thomas F.
McGraw-Hill, 1981
Buku Teks