Mobile messaging as surveillance tool during pandemic (H1N1) 2009, Mexico. Author(s): Lajous M, Danon L, López-Ridaura R, Astley CM, Miller JC, Dowell SF, O'Hagan JJ, Goldstein E, Lipsitch M|Journal: Emerg Infect Dis|PMID: 20735942| September 2010