Porter, M. (1985). Competitive advantage. Free press.
Chicago-čujuhus (17. p.)Porter, Michael. Competitive Advantage. New york: Free press, 1985.
MLA-čujuhus (9. p.)Porter, Michael. Competitive Advantage. Free press, 1985.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.