Hole, C.B., author
ELBS and Macmillan Education, 1997
Buku Teks
Meadows, P.S., author
John Wiley & Sons, 1988
Buku Teks
Sumich, James L., author
Wm.C. Brpwn, 1992
Buku Teks
Stanley, Melissa, author
Addison-Wesley, 1984
Buku Teks
Bitton, Gabriel, author
John Wiley & Sons, 1980
Buku Teks