Calloway, J. (2005). Indispensable: How to become the company that your customers can't live without. J. Wiley.
Chicago-Zitierstil (17. Ausg.)Calloway, Joe. Indispensable: How to Become the Company That Your Customers Can't Live Without. Hoboken, N.J: J. Wiley, 2005.
MLA-Zitierstil (9. Ausg.)Calloway, Joe. Indispensable: How to Become the Company That Your Customers Can't Live Without. J. Wiley, 2005.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.