Bradley D.Cramer,Daniel J. Condon, Ulf Söderlund, Carly Marshall, Graham J. Worton, Alan T. Thomas, Mikael Calner, David C. Ray, Vincent Perrier, Ian Boomer, P. Jonathan Patchett, Lennart Jeppsson:U-Pb (zircon) age constraints on the timing and duration of Wenlock (Silurian) paleocommunity collapse and recovery during the “Big Crisis”. In: Geological Society of America (Bulletin). 124. Jahrgang, Nr.11–12, Oktober 2012, S.1841–1857, doi:10.1130/B30642.1 (englisch, researchgate.net[PDF]).
Bradley D.Cramer,Daniel J. Condon, Ulf Söderlund, Carly Marshall, Graham J. Worton, Alan T. Thomas, Mikael Calner, David C. Ray, Vincent Perrier, Ian Boomer, P. Jonathan Patchett, Lennart Jeppsson:U-Pb (zircon) age constraints on the timing and duration of Wenlock (Silurian) paleocommunity collapse and recovery during the “Big Crisis”. In: Geological Society of America (Bulletin). 124. Jahrgang, Nr.11–12, Oktober 2012, S.1841–1857, doi:10.1130/B30642.1 (englisch, researchgate.net[PDF]).