Bennett, Paul, author
Open University Press, 2003
Buku Teks
Illinois, 1983
Buku Teks
Phares, E. Jerry, author
Cole Publishing, 1992
Buku Teks
Sarafino, Edward P., author
John Wiley & Sons, 1994
Buku Teks
Sarafino, Edward P., author
John Wiley & Sons, 1990
Buku Teks