De Vries, Mary Ann, author
Prentice-Hall, 1995
Buku Referensi
De Vries, Mary Ann, author
[Publisher not identified], 1978
Buku Teks
Boston: Houghton: 1993,
Buku Referensi
Mager, N. H., author
Prentice-Hall, 1975
Buku Referensi
Bay Books, 1986
Buku Referensi