Gaya APA

Agoestyowati, R. (2014). How to write effective business letter (Cet. 1). Jakarta: Lentera Ilmu Cendekia.

Gaya MLA

Agoestyowati, Redjeki.. "How to write effective business letter". Cet. 1 Jakarta: Lentera Ilmu Cendekia, 2014. Printed Book.