Sommer, Barbara Baker, A practical guide to behavioral research : tools and techniques / Barbara Sommer, Robert Sommer. - 4th ed. - New York : Oxford University Press, 1997. - xviii, 376 p. : ill. ; 25 cm. ISBN: 0195104196 (paper : acidfree paper) 0195104188 (acidfree paper) Subjects--Topical Terms: Social sciences--Research.Social sciences--Methodology.Psychology--Research.Social sciences--Research--Data processing. Dewey Class. No.: 150.72 / SOM N97P