Jones, Graham, author
McGraw-Hill, 1988
Buku Teks
Gunton, Tony, author
NCC Blackwell, 1993
Buku Teks
Brown, Wendy E., author
McGraw-Hill, 1993
Buku Referensi
Rosenberg, Jerry M., author
McGraw-Hill, 1992
Buku Referensi
Vaillancourt, Pauline M., author
Bowker, 1980
Buku Teks