Morrisey, George L., author
Addison-Wesley, 1977
Buku Teks
Guba, Egon G., author
Jossey-Bass , 1981
Buku Teks
Latino, Robert J., author
CRC Press, 2011
Buku Teks
Hamilton, Cheryl
Wods Worth Publishing, 1993
Buku Teks
Bean, Roger, author
AMACOM, 2002
Buku Teks