Nierenberg, Alan H., author
American Management Association, 2005
eBooks
Martin, Carole, author
McGraw-Hill, 2012
Buku Teks
Moffatt, Thomas L.
Harper & Row , 1979
Buku Teks
Popovich, Igor S., author
Abdi Tandur, 1996
Buku Teks
McGraw-Hill/Glencoe, 2003
Buku Teks