Cever, Francisco Asensio
Hongkong : Page One Publishing, 1996,
Buku Referensi
Cerver, Francisco Asensio, author
Page One, 1996
Buku Referensi
Dickinson, Duo, author
McGraw-Hill, 1995
Buku Teks
edited by Peter Cook, Nell Spiller
Academic Edition, 1999
Buku Teks
edited by Ismail Serageldin
Academy Editions, 1996
Buku Teks