Hill, Charles W.L.
Global business today
McGraw-Hill Irwin, 2003
 Buku Teks
Bovee, Courtland L.
Business communication today
McGraw-Hill, 1993
 Buku Teks
Bovee, Courtland L.
Business communication today
Prentice-Hall, 2005
 Buku Teks
Ogawa, Eiji
Small business management today
[Publisher not identified], 1994
 Buku Teks
Bovee, Courtland L.
Business communication today
McGraw-Hill, 1992
 Buku Teks