Gaya APA

Katzenstein, H., Sachs, W, S. (1992). Direct marketing / Herbert Katzenstein, William S. Sachs (Cet.7). New York: Macmillan Publishing.

Gaya MLA

Katzenstein, Herbert., Sachs, William, S.. "Direct marketing / Herbert Katzenstein, William S. Sachs". Cet.7 New York: Macmillan Publishing, 1992. Textbook.