Camilleri, Joseph, author
Macmillan of Australia, 1987
Buku Teks
Henni Oktaviani, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1999
UI - Skripsi (Membership)
Tahkur, Ramesh, author
Westview Press, 1986
Buku Referensi
edited by Gordon Greenwood and Norman Harper
F.W. Cheshire, 1957
Buku Teks
edited by Gordon Greenwood and Norman Harper
F.W. Chesire, 1968
Buku Teks