Reeve, Johnmarshall, author
John Wiley & Sons, Inc., 2015
Buku Teks
Cattell, Raymond B., author
World Book, 1957
Buku Klasik
edited by Chalmers L. Stacey and Manfred F. DeMartino
Howard Allen, 1958
Buku Teks
edited by Marilynn B. Brewer and Miles Hewstone
Blackwell, 2004
Buku Teks
Maslow, Abraham H., author
Harper & Row, 1970
Buku Teks SO