Magnitude 8 and Greater Earthquakes Since 1900. Earthquake Hazards Program. U.S. Geological Survey. [20 March 2011; no publication date; modified March 11, 2011]. (原始内容存档于2016-04-14).请检查|access-date=中的日期值 (帮助)
Magnitude 8 and Greater Earthquakes Since 1900. Earthquake Hazards Program. U.S. Geological Survey. [20 March 2011; no publication date; modified March 11, 2011]. (原始内容存档于2016-04-14).请检查|access-date=中的日期值 (帮助)