Short-Sale literature, courses and recommendations, CO

Hello!! I'm a real-estate investor out of Colorado looking for any must reads, books or courses etc that pertain to short-sales. I've listed which books and CD's I've read or listened to so far. As of now I'd like to stay away from Guru's but am open to any courses, classes or books that deal with short sales, I'm considering taking a pre-license real estate course in Colorado mainly for educational purposes vs. becoming an actual real estate agent (any thoughts on this idea??).

"Rich Dad Poor Dad" by Robert Kiyosaki
"Short-Sale Pre-Foreclosure Investing" by Dwan Bent-Twyford, Sharon Restrepo
"The Ultimate Guide to Buy and Hold" by William Bronchick (CD's)
"Real Estate Short Sales 2013" by Jean-Jacques Dege
Reading:

"I Love Short Sales : The Real Estate Agent's 15 Minute System for Short Sale Profits" by Charlotte Allred

Thank You in advance for your time!
Chris Manganello