Baumback, Clifford M., author
Prentice-Hall, 1975
Buku Teks
Holt, David H., author
Prentice-Hall, 1992
Buku Teks
Lerner, Joshua, author
John Wiley & Sons, 2012
Buku Teks
Institute of technology management and entreprreneurship, kolej universiti teknikal kebangsaan malaysia,
Majalah, Jurnal, Buletin
Schollhammer, Hans, author
John Wiley & Sons, 1979
Buku Teks