This paper is in the following e-collections/theme issues:

ISRII Theme Issue 2013  Research Participants Recruitment and Engagement 

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Works citing "Using Google AdWords for International Multilingual Recruitment to Health Research Websites"

Margaret S Gross, Nancy H Liu, Omar Contreras, Ricardo F Muñoz, Yan Leykin
J Med Internet Res 2014 (Jan 20); 16(1):e18 

According to Crossref, the following articles are citing this article (DOI 10.2196/jmir.2986):

(note that this is only a small subset of citations)

1. Gill S, Contreras O, Muñoz RF, Leykin Y. Participant retention in an automated online monthly depression rescreening program: Patterns and predictors. Internet Interventions 2014;1(1):20 [CrossRef]