of events online free Morris, Richard B. and Graham W. Irwin, eds. Harper Encyclopedia of the Modern World: A Concise Reference History from 1760 to the Present (1970) online Pindyck, Robert S. "What we know and don’t know about climate change, and implications for policy." Environmental and Energy Policy and the Economy 2.1 (2021): 4–43. online Pollard, Sidney, ed. Wealth and Poverty: an Economic History of the 20th Century (1990), 260 pp; global perspective online free Stearns, Peter, ed. The Encyclopedia of World History (2001) External links The 20th Century Research Project (archived 26 February 2012) Slouching Towards Utopia: The Economic History of the Twentieth Century (archived 6 February 2012) Discovering Literature: 20th century at the British Library 2nd millennium Centuries Late modern period