Robert B. Ekelund, R. F. H. (1975). A HISTORY OF ECONOMIC THEORY AND METHOD. Mc. Graw-Hill book company.
Lua i Stíl Chicago (17ú heag.)Robert B. Ekelund, Robert F. Hebert. A HISTORY OF ECONOMIC THEORY AND METHOD. Mc. Graw-Hill book company, 1975.
Lua MLA (8ú heag.)Robert B. Ekelund, Robert F. Hebert. A HISTORY OF ECONOMIC THEORY AND METHOD. Mc. Graw-Hill book company, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.