Gaya APA
Hariyanto, S., Sinubyo, . (2006).
English business correspondence : a practical guide for business and secetarial students and professional scretaries .
Yogyakarta:
Kanisius.
Gaya MLA
Hariyanto, Sugeng., Sinubyo, .
"English business correspondence : a practical guide for business and secetarial students and professional scretaries".
Yogyakarta:
Kanisius,
2006.
Text.