I strongly reccomend them. I read ringer at 15 and it completely changed my life Here's a taste. http://bookoutlines.pbworks.com/w/page/14422735/Winning Through Intimidation
Here is some more color on Dalio's thought process--- the more I learn about this guy, the more I like him.... http://www.bwater.com/Uploads/FileManager/research/All-Weather/All-Weather-Story.pdf
My opinion: His ideas on correlation are not the traditional. He has gone on record saying that there is no such thing as correlation. Just because two instruments are mathematically correlated, does not mean that the fundamentals that drive the instruments are related. It could be by chance. So, he takes it further to find drivers that may have lapping correlation but ultimately "uncorrelated". Something along that lines. Pls don't read to much into what I've said. I've just tried to explain it a bit for you. You would understand it better by reading his stuff to understand where he is coming from.