Hill, Craig A., author
Sage Publications, 2008
Buku Teks
Larsen, Randy J., author
McGraw-Hill, 2008
Buku Teks
edited by Gregory J. Boyle, Donald H. Saklofske, Gerald Matthews
Academic Press, 2015
eBooks
Kathe Schneider, editor
[Springer, ], 2012
eBooks
Mussen, Paul Henry
"Harper , 1956
Buku Teks