Vincenzo Della Mea Eddy Maddalena Stefano Mizzaro Crowdsourcing to Mobile Users: A Study of the Role of Platforms and Tasks. 14-19 2013 DBCrowd https://ceur-ws.org/Vol-1025/research2.pdf conf/dbcrowd/2013 db/conf/dbcrowd/dbcrowd2013.html#MeaMM13