Gaya APA
Guide to Professional & Business Correspondence. (2001).
:
.
Gaya Chicago
Guide to Professional & Business Correspondence.
2001.
:
,
2001.
Text.
Gaya MLA
Guide to Professional & Business Correspondence.
2001.
:
,
2001.
Text.
Gaya Turabian
Guide to Professional & Business Correspondence.
:
,
2001.
Print.