Lucas chess(https://lucaschess.pythonanywhere.com/)
Chess Tactics puzzle Book example:
(https://www.amazon.com/Winning-Sacrifices-Combinations-Reinfeld-Classics/dp/1936490870/ref=as_li_ss_tl?ie=UTF8&qid=1472869729&sr=8-1&keywords=reinfeld+1001+21st&linkCode=sl1&tag=cheboorev-20&linkId=076da44483f0c3bba0bfdf8a85a032e9)