Carney, Edward, translator
Routledge,, 1997
Buku Teks
Basch, Lester D.
Sterling Publishing , 1962
Buku Teks
Mudd, Norma
Hodder & Stoughton Educational , 1998
Buku Teks
Burt, Angela
Stanley Thornes, 1995
Buku Referensi
editor, Bud Wileman, Robin Wileman, Bessana C. Sewell
Wileman Publications, 1986
Buku Referensi