Lutz, Vera
Oxford University Press , 1962
Buku Teks
Benham, Frederic
New York, N.Y. Sir Issac Pitman 1941,
Buku Teks
Benham, Frederic
New York, N.Y. Pitman 1947,
Buku Teks
Milner, Frederic
Macmillan, 1931
Buku Teks
Gearge Allen & Unwin, 1962
Buku Teks