Is Grade repetition always wasteful? new data and unanswered questions /

Is Grade repetition always wasteful? new data and unanswered questions / John Schwille... (et al.) - - USA : Harvard University Institute for International Development, 1991. - iv, 21 p. ; il., fot. - BRIDGES Research Report Series ; 7. .

371.212. 72 (675.97) =20GRA No.7.