Gay, L. R. Educational research : Competencies for analysis and applications / L.R. Gay, Peter Airasian. - 7th ed. - Upper Saddle River, N.J. : Merrill/Prentice Hall, 2003. - xvii, 605 p. : ill. (some col.) ; 27 cm. Includes bibliogr. references and indexes. ISBN: 0130994634 Subjects--Topical Terms: Education research.