Hi

I just wanted to let you know about this convenient PDF I have no affiliation to. You might want to try it out if you are now into math or deep coding? It is a small charge but might be worthy trying out. Let me know how it is if you order it. 

Thanks 

PS. I just wanted to know what specifics you look for when validating the track records of gurus you are interested in following. Just respond to let me know. I have my standards as well.