Disclaimer: sorry if this type of post isn't allowed, I couldn't see anything about it in the rules
Writing a research essay about the causes of the end of the Cold War, need lots of sources. Thanks guys.
Melvyn Leffler, For the Soul of Mankind (covers the entire Cold War; just look at relevant chapters).
Mary Sarotte, 1989
Vladislav Zubok, A Failed Empire: The Soviet Union in the Cold War from Stalin to Gorbachev (relevant chapters)
John Lewis Gaddis, Strategies of Containment: A Critical Appraisal of American National Security Policy during the Cold War (relevant chapters)
Cambridge History of the Cold War, vol. III: Endings
Beth Fischer, The Reagan Reversal
The Global 1989: Continuity and Change in World Politics, ed. George Lawson and Chris Armbruster (especially the introduction and conclusion)
For a different view of the Cold War and it's relation to 20th century history, see Charles S. Maier "Consigning the 20th Century to History: Alternative Narratives for the Modern Era" American Historical Review 105(3): 807-831
This should provide a good foundation, but let me know if you'd like more.