Buckley, E. A. (1961). How to increase sales with letters. McGraw Hill book company.
استشهاد بنمط شيكاغوBuckley, Earle A. How to Increase Sales with Letters. New York: McGraw Hill book company, 1961.
MLA استشهادBuckley, Earle A. How to Increase Sales with Letters. McGraw Hill book company, 1961.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.