I've been studying Chess Tactics for Kids. Someone on this forum suggested it, and it's a really helpful book. ...
https://web.archive.org/web/20140708233318/http://www.chesscafe.com/text/review394.pdf
http://www.gambitbooks.com/pdfs/Chess_Tactics_for_Kids.pdf
https://web.archive.org/web/20140708234438/http://www.chesscafe.com/text/hansen15.txt
https://web.archive.org/web/20140708092459/http://www.chesscafe.com/text/review395.pdf
… Marovic is great. His "Understanding Pawn Play in Chess" and "Dynamic Pawn Play in Chess" are excellent books also. If you're ever tempted to study Kmoch's famous work, do those two books first. They cover much of the same ground in a much more understandable way.
https://web.archive.org/web/20140708110136/http://www.chesscafe.com/text/review249.pdf
http://theweekinchess.com/john-watson-reviews/books-of-many-flavours
... I also read silman complete endgame
https://web.archive.org/web/20140708103149/http://www.chesscafe.com/text/review594.pdf
http://theweekinchess.com/john-watson-reviews/theres-an-end-to-it-all
https://www.silmanjamespress.com/shop/chess/silmans-complete-endgame-course/