Boundaries Book is Great Resource for Sales People for Business
Boundaries: When to Say YES, When to Say NO, To Take Control of Your Life is a wonderful book full of stories that help you understand what is going on under the hood with your relationships. Dr. Henry Cloud and Dr. John Townsend put together practical solutions in story form that show you how to better manage your life and business, all the while having more peace and less stress. I highly recommend this book.
Boundaries: When to Say YES, When to Say NO, To Take Control of Your Life