Validity in survey research : with special reference to the techniques of intensive interviewing and progressive modification for testing and constructing difficult or sensitive measures for use in survey research : a report
|aValidity in survey research|b: with special reference to the techniques of intensive interviewing and progressive modification for testing and constructing difficult or sensitive measures for use in survey research : a report|c/ by William A. Belson ; based upon research under the direction and control of William Belson ; with participation by J.G. Cleland ... [et al.].