Waddy, Patricia
MIT Press, 1990
Buku Teks
Boren, Henry C., author
D.C. Heath and Company, 1977
Buku Referensi
Homo, Leon
Kegan Paul,Trench,Trubner & CO,LTD, 1927
Buku Teks
Jones, Mark Wilson
Yale University Press, 2000
Buku Teks
Nash, Ernest, author
Frederick A. Praeger, [1961-62]
Buku Referensi