Παραπομπή APA

Buckley, E. A. (1961). How to increase sales with letters. McGraw Hill book company.

Παραπομπή Chicago Style

Buckley, Earle A. How to Increase Sales with Letters. New York: McGraw Hill book company, 1961.

Παραπομπή MLA

Buckley, Earle A. How to Increase Sales with Letters. McGraw Hill book company, 1961.