Holt, Rinehart and Winston of Canada, Limited, 1988
Buku Teks
Shurter, Robert L.
McGraw-Hill, 1957
Buku Teks
McLean, Gary N., author
Paradigm Publishing, 1991
Buku Teks
Blake, Gary
McGraw-Hill, 1995
Buku Teks
Lauchman, Richard, author
American Management Association;;, 1993
eBooks