Zook, C. (2004). Beyond the Core: Expand Your Market without Abandoning Your Roots. Harvard Business Review Press.
Chicago-referens (17:e uppl.)Zook, Chris. Beyond the Core: Expand Your Market Without Abandoning Your Roots. Boston, Massachesutts: Harvard Business Review Press, 2004.
MLA-referens (9:e uppl.)Zook, Chris. Beyond the Core: Expand Your Market Without Abandoning Your Roots. Harvard Business Review Press, 2004.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.