Lewis, David, author
IPM, 1994
Buku Teks
Pitt, Gwyneth, author
Sweet & Maxwell, 2011
Buku Teks
Bennet-Alexander, Dawn, author
Irwin/McGraw-Hill, 2004
Buku Teks
Carr, Chris J., author
Pitman, 1994
Buku Teks
Twomey, David P.
South-Western Publishing Company, 1986
Buku Teks