Gaya APA

F.W, K., Ann, C, D. (1980). English Business Letters Commercial Correspondence for Foreign Students Revised by David O'Gorman (New Edition). Yogyakarta: Penerbit Yayasan Kanisius.

Gaya MLA

F.W, King., Ann, Cree, D.. "English Business Letters Commercial Correspondence for Foreign Students Revised by David O'Gorman". New Edition Yogyakarta: Penerbit Yayasan Kanisius, 1980. Text.