V. Seveschen, "The Eastern European Revolution 1989: The Collapse of the Soviet Empire" - A great book to learn about the history of the collapse of the communist bloc!
Seveschen's works are just easy to read, and they are all great books that lead us to interesting yet deep insights.
This book looks at society at the end of the Cold War from a large global perspective. It is also a masterful book that analyzes the process of its collapse in chronological order and also highlights the interrelationships among the different countries. This is an excellent work. A gem that you will want to read over and over again!