Bussmann, Hadumod, author
Routledge, 1996
Buku Referensi
Longman, 1984
Buku Referensi
edited by Henry Cecil
George Routledge & Sons, 1946
Buku Referensi
Brown, Kenneth, author
Charles Darwin University Press, 2005
Buku Teks
Corris, Peter
University Press, 1973
Buku Teks