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
Winston, Robert ML
BBC Worldwide Limited, 2004
Multimedia
Winston, Robert ML
BBC Worldwide Limited, 2004
Multimedia