Text ( visual ) : unmediated Educational research : competencies for analysis and applications / L.R. Gay, Geoffrey E. Mills, Peter Airasian. -- 9th ed. -- London : Merrill, Pearson Education International , c2009. -- xvi, 618 p. : ill. ; 26 cm. -- (Pearson international edition). -- Previous ed.: Englewood Cliffs, N.J.; London: Prentice Hall, 2006 ; Includes bibliographical references and index. -- ISBN 9780136040941 ; (BA91350508) ; https://ci.nii.ac.jp/ncid/BA91350508 Author Heading(s): Gay, L. R. ; Mills, Geoffrey E. ; Airasian, Peter W.. -- Classification(s): DC22 : 370.72. -- Subject Heading(s): LCSH : Education -- Research