Παραπομπή APA

Ferber, R., & Verdoorn, P. (1962). Research methods in economics and business. Macmillan company.

Παραπομπή Chicago Style

Ferber, Robert, και P.J Verdoorn. Research Methods in Economics and Business. London: Macmillan company, 1962.

Παραπομπή MLA

Ferber, Robert, και P.J Verdoorn. Research Methods in Economics and Business. Macmillan company, 1962.