Enzo,
At a moment there is no any idea about T-64 (while I have excellent line drawings for it - highly recommend a great "T-64" book by Vasiliy Chobitok, who is good friend of mine).
As for Concord drawings: Most of their drawings need some corrections/additions.
Hard to tell You good source for drawings (at least "M-Hobby" drawings are usually very accurate and they do publish a digest with all/or most drawings printed during a year). The other sources are very individual....
Good source for books to be bought from a Web is Armybook company (sometimes slightly more expensieve than can be found in other places, but a good choice of items in stock).
As for a specialized bookshop in Kiev: The one at the Oleny Teligi str. #35 is recommended.
Sincerely Alexey.
http://www.acemodel.com.ua