Quible, Zone K.
Business Communication
Prentice-Hall International, 1996
 Koleksi Publik
Ewald, Helen Rothschild
Business communication
Prentice-Hall International, 1997
 Buku Teks
Krizan, A.C.
Business communication
Thomson, 2008
 Buku Teks SO
Ewald, Helen Rothschild
Business communication
Prentice-Hall International, 1997
 Buku Teks
Business communication
by LaJuana Williams Lee ... [and others]
Houghton Miffiln, 1980
 Buku Teks SO