Kurihara, Kenneth K.
George Allen and Unwin , 1963
Buku Teks
Moore, Kenneth D.
Random House , 1989
Buku Teks SO
Posner, Richard A.
Litle, Brown, 1980
Buku Teks SO
Garland , 1993
Buku Teks
edited by John Eatwell, Murray Milgate and Peter Newman
Macmillan, 1988
Buku Referensi