Edward Arnold, 1978
Buku Teks
edited by Henry Mayer
F.W. Chesire, 1966
Buku Teks
Theophanous, Andrew C.
Oxford University Press, 1980
Buku Teks
University of Queensland, 1968
Buku Teks
Crisp, L. F. (Leslie Finlay), author
Longman Chesire, 1965
Buku Teks