Boxill, Roger, author
Macmillan, 1994
Buku Teks
Williams, Tennessee
Penguin Books , 1964
Buku Teks
Wawan Christiawan, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2002
UI - Tesis (Membership)
Pritchett, C. Herman, author
University of North California Press, 1943
Buku Teks
Pritchard, Jack A., author
Airlangga University , 1991
Buku Teks