@PATAX I've used the All States Quickfinder in the past, but lately, I've found that going directly to the specific state's website is more informative. The Quickfinder has basic information for each state, which sometimes is enough, but it does not often have the specific information for which I am looking.   

I've used the printed copies of the Quickfinders in the past, but I've been looking at The Taxbook website, and am considering "Jacob's Special" because it includes WebLibrary Plus which looks like it would be an excellent resource. TTB - Products (thetaxbook.com)

I'm also considering the Parker Tax Pro Library Tax Research Products - Parker Tax Pro Library - Product (parkertaxpublishing.com) which is another online library. One thing that is very attractive is the Search Engine. I don't see a search engine on The Taxbook's website. Parker has a special 25% off offer that expires tomorrow.