Linda P. Bourque, Eve P. Fielder
Thousand Oaks : SAGE PUBLIKATION, 2003,
Buku Referensi
Hoxley, Mike
[RIBA , ], 2009
eBooks
Roman, Murray
McGraw-Hill, 1976
Buku Teks
Ullmann, Manfred
Edinburgh University Press, 1978
Buku Teks
Anderson, Kristin
American Management Association, 1992
eBooks