1. Dillman DA, Smyth JD, Christian LM. Internet, Phone, Mail, and Mixed-Mode Surveys: The Tailored Design Method. 4th ed. New Jersey: John Wiley and Sons; 2014.
2. Finamore J, Dillman DA. How mode sequence affects response by internet, mail, and telephone in the National Survey of College Graduates. In: Paper presented at the European Survey Research Association Biennial Conference. Ljubljana, Slovenia. 2013.
3. Smyth JD, Dillman DA, Christian LM, O’Neill A. Using the Internet to survey small towns and communities: Limitations and possibilities in the early 21st century. Am Behav Sci. 2010;53:1423–48.
4. Gentry R. Offering respondents a choice of survey mode. In: Paper presented at CMOR Respondent Cooperation Workshop: March 2008; Las Vegas,NV. 2008.
5. Medway R, Fulton J. When more gets you less: A meta-analysis of the effect of concurrent web options on mail survey response rates. Public Opin Q. 2012;76(4):733–46.