Routledge, 1998
Buku Teks
edited by George R. Creeger and Joseph W. Reed, Jr.
Holt, Rinehart and Winston, 1964
Buku Teks
Stafford, Fiona, author
Wiley Blackwell, 2012
Buku Teks
Fischer, Hermann, author
Cambridge University Press, 1991
eBooks
edited with introduction by David Wright
Penguin Books, 1982
Buku Referensi