Schnore, Leo F.
The Free Press, 1965
Buku Teks
Levy, Leo
Behavioral Publ., 1973
Buku Teks
Forman, Richard T. T., author
Cambridge University Press, 2014
Buku Teks
Parris, Kristen M., author
John Wiley & Sons, 2016
Buku Teks
George, Carl J.
McGraw-Hill, 1974
Buku Teks