Sherman, Andrew J.
American Management Association, 2006
eBooks
Weston, John Fred, 1916-
McGraw-Hill, 2001
Buku Teks
Partner, Simon
New Jersey, Prentice Hall1991,
Buku Referensi
Coyle, Brian
Canterbury CIB , 2000
Buku Teks
Gaughan, Patrick A.
John Wiley & Sons, 2002
Buku Teks SO