Gemmill, P. F. (1948). Economics: Principles and problems (3rd ed. vol. 1 & 2.). Harper.
Lua i Stíl Chicago (17ú heag.)Gemmill, Paul F. Economics: Principles and Problems. 3rd ed. vol. 1 & 2. New York: Harper, 1948.
Lua MLA (9ú heag.)Gemmill, Paul F. Economics: Principles and Problems. 3rd ed. vol. 1 & 2. Harper, 1948.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.