American Psychological Association, 1985
Buku Teks
Cronback, Lee J.
Harper International Student , 1964
Buku Teks
Cohen, Ronald Jay, author
Mayfield Publishing Company, 1999
Buku Teks
Cronbach, Lee J
Harper and Row, 1970
Buku Teks
Brown, Frederick G., author
Dryden Press, 1970
Buku Teks