Churchill, Gilbert A., author
Thomson, 2005
Buku Teks
Cooper, Donald R., author
McGraw-Hill/Irwin, 2006
Buku Teks
by David A. Aaker ... [and others]
John Wiley & Sons, 2013
Buku Teks
Lorie, James H., author
NMcGraw-Hill , 1951
Buku Teks
J. Supranto, author
Ghalia Indonesia, 1983
Buku Teks