ChristianL.M., & DillmanD.A. (2004) The influence of symbolic and graphical language on answers to paper self-administered questionnaires. Public Opinion Quarterly, 68, 1, pp. 57–80.
2.
ChristianL.M., DillmanD.A., & SmythJ.D. (2007) Helping respondents get it right the first time: the influence of words, symbols, and graphics in web surveys. Public Opinion Quarterly, 71, 1, pp. 113–125.
3.
DillmanD.A. (2000). Mail and Internet Surveys: The Tailored Design Method (2nd edn). New York: Wiley.
4.
EsslemontD., & LambourneP. (1992) The effect of wrongly addressed mail on mail survey response rates. Marketing Bulletin, 3, pp. 53–55.
5.
HealeyB. (2007) Drop downs and scroll mice: the effect of response option format and input mechanism employed on data quality in web surveys. Social Science Computer Review, 25, 1, pp. 111–128.
6.
PetersonR.A. (1984) Asking the age question: a research note. Public Opinion Quarterly, 48, 1, pp. 379–383.
7.
SmitJ.H., DeegD.J.H., & SchmandB.A. (1997) Asking the age question in elderly populations: a reverse record check study. Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 52, 4, pp. 175–177.