Voiles, Price R.
Glencoe, 1993
Buku Teks
Tomasowa, Francien Herlen
Universitas Brawijaya , 2005
Buku Teks
Tomasowa, Francien Herlen
Universitas Brawijaya, 2005
Buku Teks
Eastwood, John
Oxford University Press, 1994
Buku Teks
Scobie, Janet I.
George Allen and Unwin, 1959
Buku Teks