Anthonio akkermans, Peter G. Drake, Bill Mattos, andy Middleton
Hermes House, 2011
Buku Referensi
edited by William Wels
Lippincott Williams & Wilkins, 2003
Buku Teks
Berges, Steve, author
American Management Association, 2006
eBooks
Goncalves, Marcus, author
McGraw-Hill , 2000
Multimedia
Bobola, Daniel T., author
Alpha Books, 1995
Buku Teks