Butler, Richard P.1973. "Effects of Signed and Unsigned Questionnaires for Both Sensitive and Nonsensitive Items," Journal of Applied Psychology57 (June) 348-349.
2.
Crawford, C.M.1970. "Attitudes of Marketing Executives Toward Ethics in Marketing Research," Journal of Marketing34 (April) 46-52.
3.
Cronback, Lee J.1970. Essentials of Psychological Testing, New York: Harper & Row, Third Edition.
4.
Fuller, Carol1974. "Effect of Anonymity on Return Rate and Response Bias in a Mail Survey," Journal of Applied Psychology59 (June) 292-296.
5.
Pearlin, Leonard I.1961. "The Appeals of Anonymity in Questionnaire Response," Public Opinion Quarterly25 (Winter) 640-647.
6.
Siegel, Sidney1956. Nonparametric Statistics for the Behavioral Sciences. New York: McGraw-Hill.
7.
Snedecor, George W., and William G. Cochran1967. Statistical MethodsAmes: The Iowa State University Press, Sixth Ediction.