Gaya APA

Samuelson, P, A., Nordhaus, W, D. (2005). Economics Eigthteenth ed. . Boston: Mc Graw-Hill.

Gaya MLA

Samuelson, Paul, A., Nordhaus, William, D. "Economics Eigthteenth ed.". Boston: Mc Graw-Hill, 2005. BUKU PENGAYAAN.