00457nam a2200169Ia 4500082001700000100001700017245006500034260002400099300000900123500000500132690000600137700000500143952009800148964001700246921000900263999001500272  a370bP719.RE  aPlatt, W. J.  aResearch for educational planning; notes on emergent needsb  aParisbUnescoc1970  a67p.  a  a   a  00104070aISIbISId1998-09-02l0o370 P719.REpDP4739r2019-02-14 00:00:00w2019-02-14yBK  abcdefg  a7809  c7809d7809