Porter, M. (2004). Competitive Advantage (1st.). Free Press.
Chicago-čujuhus (17. p.)Porter, Michael. Competitive Advantage. 1st. Free Press, 2004.
MLA-čujuhus (9. p.)Porter, Michael. Competitive Advantage. 1st. Free Press, 2004.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.