Cohen, Ronald How to grow feet out of your ears when you land on your head : validity and sampling in an African survey. - Boston : African Studies Association, 1970. - 19p. ; 28cm. - Paper No.1 - 24 are all bound in one book. . Subjects--Topical Terms: SamplingDistributionSurvey LC Class. No.: EAF QTO DT19.9.U57A351970No.13