I think the list mr_luc is referencing is in the second answer on this page: http://www.paulgraham.com/raq.html

EDIT: Here's the whole list, for completeness: Clark, Civilisation White, Medieval Technology and Social Change McEvedy, Penguin Atlases of Ancient and Medieval History Laslett, The World We Have Lost Bernal, The Extension of Man Franklin, Autobiography Girouard, Life in the English Country House Pirenne, Mohammed and Charlemagne Runciman, The Fall of Constantinople Cipolla, Guns, Sails and Empires Hadas, A History of Rome Oman, The Art of War in the Middle Ages Vasari, Lives of the Artists Bovill, The Golden Trade of the Moors Caesar, Gallic Wars Kuhn, The Copernican Revolution