Buku Referensi
Freeman, Roger L., author
Wiley, 1985
Buku Referensi
Lindeburg, Michael R., author
Professional Publications, 1984
Buku Teks
Harbison, Samuel P., author
Prentice-Hall, 1995
Buku Referensi
Garrison, Catherine, author
Reading, Mass Addison-Wesley Publishing Co , 1989
Buku Teks