APA استشهاد

Heal,Geoffrey. (1999). The economics of increasing returns. Edward Elgar.

استشهاد بنمط شيكاغو

Heal,Geoffrey. The Economics of Increasing Returns. U K: Edward Elgar, 1999.

MLA استشهاد

Heal,Geoffrey. The Economics of Increasing Returns. Edward Elgar, 1999.