Robinson, Alan, author
Macmillan, 1988
Buku Teks
Bremner, G. A., author
Oxford University Press, 2016
eBooks
Stender, Thomas
Lark Books, 2000
Buku Referensi
Cever, Francisco Asensio
Hongkong : Page One Publishing, 1996,
Buku Referensi
Cerver, Francisco Asensio, author
Page One, 1996
Buku Referensi