R.Kunjana, R., Rodhi, A.(2009).Communicative english for secretaries: a comprehensive communication workbook for students of business and secretarial studies (Cet.1).Yogyakarta:Pustaka Book Publisher.
Gaya MLA
Rahardi, R.Kunjana., As'ad, Rodhi."Communicative english for secretaries: a comprehensive communication workbook for students of business and secretarial studies".Cet.1Yogyakarta:Pustaka Book Publisher,2009.Textbook.