Text ( visual ) : unmediated Educational research, an introduction / Walter R. Borg, Meredith Damien Gall. -- 3rd ed. -- New York : Longman , c1979. -- xxv, 753 p. : ill. ; 25 cm. -- Includes bibliographies and indexes. -- ISBN 0582280567 ; (BA03063678) ; https://ci.nii.ac.jp/ncid/BA03063678 Author Heading(s): Borg, Walter R. ; Gall, Meredith D.. -- Classification(s): LCC : LB1028 ; DC : 370/.78. -- Subject Heading(s): LCSH : Education -- Research