Russo, Steve, author
Pearson Benjamin Cummings, 2007
Buku Teks
Engel, Thomas, author
Pearson Prentice Hall, 2006
Buku Teks
Artikel Jurnal
Christian, Gary D., author
John Wiley & Sons, 1977
Buku Teks
Beyer, Hans, author
[Publisher not identified], [Date of publication not identified]
Buku Teks