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
Moser, Claus A., author
Heinemann Educational Books, 1973
Buku Teks
Reinharz, Shulamit
Oxford University Press, 1992
Buku Teks