Heal,Geoffrey. (1999). The economics of increasing returns. Edward Elgar.
Chicago Style aipamenaHeal,Geoffrey. The Economics of Increasing Returns. U K: Edward Elgar, 1999.
MLA aipamenaHeal,Geoffrey. The Economics of Increasing Returns. Edward Elgar, 1999.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.