Dunn, Dana S., author
Wiley-Blackwell, 2009
Buku Teks
Crano, William D., author
Lawrence Erlbaum Assossiate, 2002
Buku Teks
Goode, William J., author
McGraw-Hill, 1952
Buku Teks
by Claire Selltiz [and others]
Holt, Rinehart and Winston, 1959
Buku Teks
Black, James A., author
John Wiley & Sons, 1976
Buku Teks