Download or read book Two Kinds of Derived Categories, Koszul Duality, and Comodule-Contramodule Correspondence written by Leonid Positselski and published by American Mathematical Soc.. This book was released on 2011 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: "July 2011, volume 212, number 996 (first of 4 numbers)."