Buzo, Alex
Angus and Roberson Publishers, 1985
Buku Teks
Buzo, Alex
Currency Press, 1993
Buku Teks
Paraskos, Ski, author
Northcote House, 1993
Buku Teks
England, Alan
Macmillan Education, 1990
Buku Teks
editor, James R. Brandon
Cambridge Unipersity Press, 1993
Buku Referensi