Clymer, Theodore, author
Burdett, 1984
Buku Teks
Trimble, Louis
Cambridge University Press, 1985
Buku Teks
Gerson, Sharon J., 1948-, author
Prentice-Hall, 1992
Buku Teks
Trimble, Louis
Cambridge University Press, 1985
Buku Teks
[publisher not identified], [date of publication not identified]
Naskah