Anton, Howard, author
John Wiley & Sons, 1980
Buku Teks
Bers, Lipman
Holt, Rinehart and winston, 1969
Buku Teks
Lightstone, A. H., author
Harper & Row, 1965
Buku Teks
Lightstone, A. H., author
Harper & Row, 1965
Buku Teks
Research and Education Association, 1987
Buku Teks