Comments on: Validating the Use of Google Trends to Enhance Pertussis Surveillance in California http://currents.plos.org/outbreaks/article/validating-the-use-of-google-trends-to-enhance-pertussis-surveillance-in-california/ Thu, 20 Oct 2016 19:25:51 +0000 hourly 1 https://wordpress.org/?v=4.5.3