Klecka, William R., author
Sage, 1980
Buku Teks
Huberty, Carl J., author
John Wiley & Sons, 1994
Buku Teks
Goldstein, Matthew, author
John Wiley & Sons, 1978
Buku Teks
Mclachlan, Geoffrey J., author
John Wiley & Sons, 1992
Buku Teks
Day, R.A., author
Prentice-Hall, 1958
Buku Teks