web | Kay Jamison | YouTube | 2009-07-30 | |
web | Malcolm Ritter | Associated Press | 2009-04-30 | |
web | Michael Kahn | Reuters | 2008-07-18 | |
web | Robin Nixon | LiveScience | 2008-06-27 | |
web | Robert Roy Britt | LiveScience | 2005-05-26 | |
web | Adrian C. North, David J. Harg... | Nature | 1997-11-13 |