Originally posted by KorchI think the english version of that is named "the praxis of my system". (which is kind of a wrong translation.)
Nimzovich books in Russian ("My system", "My system in practice" ) learned me to play positionally. Books about Latvian (first one was "Latvian gambit. Made easy" by Grivainis & Elburg, second one "The Latvian gambit" by Kosten) gambit helped me to improve my tactical sight. Another very useful book for my tactic was "Attack" (in Russian) by Tal & Damsky.