Pelletier, Kenneth R., author
A Fireside Book, 2002
Buku Teks
Weisman, Roanne, author
Health Communications, Inc, 2003
Buku Teks
Drury, Nevill
Hale & Iremonger , 1983
Buku Teks
Independence Educational , 1994
Buku Teks
Labriola, Dan, author
A Division of Prima Publishing, 2000
Buku Teks