A case study on research linking an asteroid impact to dinosaur extinction that discusses the practice of science. From Understanding Science.
Nicholas Copernicus, De Revolutionibus (1543 CE). Full text of Copernicus' original work, translated into English.
Mario J. Molina & F.S. Rowland, University of California, Irvine - Full article on destruction of atmospheric ozone reprinted from Nature magazine.
National Academy of Sciences - Traces the history of the discovery of ozone, the ozone layer, and the ongoing studies of the ozone hole over Antarctica.
Google - Research database allows searching of the scholarly literature.