Wegmann, Brenda
Random House, 1985
Buku Teks
Ellis, Mark, author
Thomas Nelson and Sons, 1987
Buku Teks
Murray, Maggie, author
Oxford University Press, 1994
Buku Teks
Genzel, Rhona B.
Heinle & Heinle Pub, , 1993
Buku Teks
Dixson, Robert J., author
Regents Publishing, 1971
Buku Teks