1. Comparability of data BRFSS 2013,2014
2. Behavioral risk factor surveillance system overview: BRFSS 2016,2017
3. Statement by vice-president ansip and commissioner jourová ahead of the entry into application of the general data protection regulation,2018
4. Assessing the representativeness of public opinion surveys;Kohut,2012
5. Nonresponse in social science surveys: a research agenda;Tourangeau,2013