edited by Maurice R.G. O'Gorman, Albert D. Donnenberg
CRC Press, 2008
Buku Referensi
Clark, William R
John Wiley & Sons, 1991
Buku Teks SO
Plutchik, Robert
Harper & Row, 1983
Buku Teks SO
Valentine, Willard L.
Holt, Rinehart and Winston, 1949
Buku Teks SO
Robinson, Paul W.
Harper & Row, 1979
Buku Teks SO