Authors: Oliver G Pybus; Marc A Suchard; Philippe Lemey; Flavien J Bernardin; Andrew Rambaut; Forrest W Crawford; Rebecca R Gray; Nimalan Arinaminpathy; Susan L Stramer; Michael P Busch; Eric L Delwart Journal: Proc Natl Acad Sci U S A Date: 2012-08-27 Impact factor: 11.205