Gaya APA

II, I, K, Y., Hariyanto, S. (2006). English Business Correspondence (cet.10). Jakarta: Kanisius.

Gaya MLA

II, Indonesia.Poltekkes, Kemenkes, YogyakartaJakarta., Hariyanto, Sugeng. "English Business Correspondence". cet.10 Jakarta: Kanisius, 2006. Text.