What are the best books to read for ON LINE Single Table Sit and Go Tournaments?

I just finished reading Secrets of Sit and Go by Phil Shaw.. Honestly, I feel like I have learned a lot, but my stats have not improved much yet!.... So I am wondering if there are other books that are essential to becoming a good online sit and go player... I have heard people mention Collin Moshman and Harrington's books but not sure if they are just advertising or they are really good books... any ideas? thanks