Weiner, E.S.C., compiler
Clarendon Press, 1993
Buku Referensi
Wells, Ronald A.
Mouton, 1973
Buku Teks
Evans, Bergen, 1904-, author
Random House, 1957
Buku Referensi
Sarumpaet, J.P. (Jan Pieter)
Pitman, 1980
Buku Referensi
Nicholson, Margaret, author
Oxford University Press, 1957
Buku Referensi