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
Judd, Charles M., author
Methuen, 1991
Buku Teks
Bailey, Kenneth D., author
The free press, 1994
Buku Teks