"Techniques of Positional Play" by Valeri Bronznik and "What It Takes To Become A Chessmaster" by Andrew Soltis.
I second the Bronznik book. Its very good...
"Techniques of Positional Play" by Valeri Bronznik
Also at your level, you might like...
"Chess Tactics From Scratch...." by Martin Weteschnik
Both books are targeted to the more advanced player...
Yusupov's book are great, although to get the max out of them you MUST follow the author's work program faithfully- else they are just like any other training book.
Yes, we can get knowledge of any 6 parts of the game.