APA استشهاد

Ireland,Norman J. (1987). Product differentiation and non-price competition. Basil Blackwell.

استشهاد بنمط شيكاغو

Ireland,Norman J. Product Differentiation and Non-price Competition. New York: Basil Blackwell, 1987.

MLA استشهاد

Ireland,Norman J. Product Differentiation and Non-price Competition. Basil Blackwell, 1987.