Cretaceous-Tertiary
Impact Theory, 101 Crazy Dinosaur Theories, Dinosaur Extinction, Dinosaur Volcano Greenhouse Extinction, Dinosaurs and Extinctions, Science Daily: A World Ruled By Fungi, The End-Cretaceous (K-T) Extinction, The Great Mystery
BBC Extinction Files
Broad, non-technical coverage of the whole field; a good introductory work. Includes mass extinctions, theories, the fossil record, FAQs, and a glossary.
Extinction
A number of extinction concepts are discussed and loosely defined, followed by a survey of some important extinction and "extinction-like" events, primarily from the Phanerozoic.
Extinctions: Cycles of Life and Death Through Time
Covers patterns and periodicity of extinction, with discussions of major mass extinctions and minor extinction events.
Mass Extinction
A mathematical model for mass extinction.
Phanerozoic Extinctions
Fully referenced BSc honours project on the History of Mass Extinctions with special reference to the proposed sixth extinction taking place at the present time.
The Late Devonian Mass Extinction
A professional technical paper discussing whether the Late Devonian (Frasnian-Famennian) mass extinction was initiated by an extraterrestrial impact or an earth-bound event.