Merriam-Webster's guide to business correspondence : a merriam-webster
Merriam-Webster's, Incorporated, 1993
Buku Referensi
Wilson, Kevin
AMA handbook of business writing: the ultimate guide to style, grammar, usage, punctuation, construction, and formatting
American Management Association, 2010
eBooks
Wilson, Kevin, 1958-
AMA handbook of business writing: the ultimate guide to style, grammar, punctuation, usage, construction, and formatting
American Management Association;, 2010
eBooks
De Vries, Mary Ann
The Elements of correspondence
Macmillan, 1994
Buku Teks SO
Lesikar, Raymond Vincent
Basic business communication : skills for empowering the internet generation
McGraw-Hill/Irwin , 2002
Buku Teks SO