CCES, Common Content, 2015https://doi.org/10.7910/DVN/SWMWX8Ansolabehere, StephenSchaffner, BrianHarvard Dataverse2017-06-282018-03-21T12:42:10Z2015 Cooperative Congressional Election Study Common Content data and questionnaire. Social Sciences2017-06-28Schaffner, Brian2015-06-24CC0 1.0