Parkinson, C. Northcote (Cyril Northcote), 1909-1993, author
Federal Publications, 1992
Buku Teks
Etzel, Michael J., author
McGraw-Hill, 2004
Buku Teks
Kerin, Roger A., author
The McGraw-Hill, 2003
Multimedia
Phillips, Charles F., author
Boston , Houghton Mifflin
Buku Teks
edited by John D Bitzan, James H. Peoples, Wesley W. Wilson
Emerald, 2016
eBooks