Monk, Andrew, author
John Wiley & Sons, 1991
Buku Teks
Field, Andy, author
Sage Publications, 2009
Buku Teks
Connolly, T.G.
Hafner , 1953
Buku Teks
Little, Todd D, author
The Guilford Press, 2013
Buku Teks
Gravetter, Frederick J., author
Salemba Empat, 2014
Buku Teks