References
A Guide to the Project Management Body of Knowledge (PMBOK® Guide) – Fourth Edition
Project Management Institute, Inc. (PMI®), © 2008

Project Management: A Systems Approach to Planning, Scheduling, and Controlling, 10th Edition
Harold Kerzner, Ph.D
John Wiley & Sons, Inc., ©2009

Copyrights
PMI® and PMBOK® are registered trademarks and CAPM® is a registered certification mark of the Project Management Institute, Inc., registered in the United States and other nations.