1. Standard Definitions: Final Dispositions of Case Codes and Outcome Rates for Surveys;AAPOR,2009
2. Agency for Healthcare Research and Quality, 2008. MEPS-HC Response Rates by Panel.
3. Multiple Regression: Testing and Interpreting Interactions;Aiken,1991
4. Generations, cohorts and social change;Alwin,2003
5. American National Election Studies, 2004. The 2004 National Election Study. University of Michigan, Center for Political Studies, Ann Arbor, MI, pp. dataset.