Blake, Gary
McGraw-Hill, 1995
Buku Teks
Fitzgerald, Suzanne Sparks
McGraw-Hill, 2011
Buku Teks
Lauchman, Richard, author
American Management Association;;, 1993
eBooks
by Geraldine Henze
Richard D. Irwin, 1984
Buku Teks
Quible, Zane K., author
Prentice-Hall, 1996
Buku Teks