Williams, L.A. (Leonard Aimslie), 1909-
American Elsevier Publishing Company, INC, 1968
Buku Teks
Crisp, Richard D., author
McGraw-Hill, 1957
Buku Teks
Aaker, David A., author
John Wiley & Sons, 2000
Buku Teks
Wilson, R. M. S., author
Heinemann, 1973
Buku Teks
Kinnear, Thomas C., 1943-, author
McGraw-Hill, 1996
Buku Teks