Wong, Abdullah, author
Noura Books, 2013
Buku Teks
edited by David Dunning and David Dunning
Psychology Press, 2011
Buku Teks
Shinn, George, author
Interaksara, 2003
Buku Teks
Cattell, Raymond B., author
World Book, 1957
Buku Klasik
Steers, Richard M., compiler
McGraw-Hill, 1991
Buku Teks