Agile Software Development with Scrum by Ken Schwaber and Mike Beedle, ISBN: 0130676349
Also known as ScrumBook on this wiki
"Most executives today are not happy with their organization's ability to deliver systems at reasonable cost and timeframes. Yet, if pressed, they will admit that they don't think their software developers are not competent. If it's not the engineers, then what is it that prevents fast development at reasonable cost? Scrum gives the answer to the question and the solution to the problem. — Alan Buffington, industry consultant, former Present, Fidelity Systems Company