APA aipamena

 Frank, R. H. (2011).  Principles of economics.  McGraw-Hill.

Chicago Style aipamena

 Frank, Robert H.  Principles of Economics.  McGraw-Hill, 2011.

MLA aipamena

 Frank, Robert H.  Principles of Economics.  McGraw-Hill, 2011.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.