海量图书期刊资源，随时随地畅享阅读乐趣
Does Requesting Sensitive Information on Postal Questionnaires Have an Impact on Response Rates? A Randomised Controlled Trial in the South West of EnglandTim J. Peters, Ian M. Harvey, Max O. Bachmann and Jenny I. Eachus · Journal of Epidemiology and Community Health (1979-) · 1998