Danni Junus, author
Gagas Media, 2004
Buku Teks
Kay, David C., author
IDG Books, 2001
Buku Teks
Kinsella, WP
Oberan Press, 1981
Buku Teks
Maclean, Catherine Macdonald
New York The Macmillan Company 1944
Buku Teks
Braggiotti, Gloria
Thomas Y. Crowell, 1957
Buku Teks