Gaya APA

Zaiss, C, D., D, T, G, P. (1993). Sales Effectiveness Training (Cet. Pertama). New York: Penguin Group.

Gaya MLA

Zaiss, Carl, D.., D, Thomas, Gordon,, Ph.. "Sales Effectiveness Training". Cet. Pertama New York: Penguin Group, 1993. BUKU.