Coultas, Barbara
Teach Yourself Books, 1990
Buku Teks
Bower, Malcolm
Hodder & Stoughton, 1977
Buku Teks
Foley, James D.
John Benjamins B. V., 1979
Buku Teks
Moffatt, C.W. Paget
University Tutorial Press, 1`929
Buku Teks
Mont, Francis M Du
Barnes & Noble , 1947
Buku Teks