Gaya APA

King, F., Cree, D, A. (1979). English Business Letters: commercial, correspondence for foreign students. New Edition (Ed.2). Singapore: Longman Group Limited.

Gaya MLA

King, F.W.., Cree, D., Ann. "English Business Letters: commercial, correspondence for foreign students. New Edition". Ed.2 Singapore: Longman Group Limited, 1979. Textbook.