Gay, L. R. Educational research : competencies for analysis and applications / L. R. Gay, Geoffrey E. Mills, Peter Airasian - 8th ed. - Upper Saddle River, N. J. : Pearson / Merrill / Prentice Hall, 2006 - xix, 614 p. : ill. ; 27 cm. Includes bibliographical references and indexes ISBN: 0131185349 RM314.16 Subjects--Topical Terms: Education--Research