Cohen, Ronald Jay, author
Mayfield Publishing, 2006
Buku Teks
Cohen, Ronald Jay, author
Mayfield Publishing Company, 1999
Buku Teks
Swerdlik, Mark E.
Mayfield Publishing Company, 1999
Buku Teks
Nunnally, Jum C., author
McGraw-Hill, 1970
Buku Teks
Anastasi, Anne, author
Prentice-Hall, 1997
Buku Teks