00586nam a22001812  4500001001100000005001700011008004100028020003300069040001500102050002100117100003300138245003900171260005400210300001400264650004600278650004700324700003300371000000424220151217145800.0070521s        xx            000 0 eng d  a0262510375 :cKES 200 (don.)  aKABUcKABU 0aQA462b.A23 19811 aAbelson, Harold.@000015470510aTurtle geometry /cHarold Abelson.  aCambridge, Massachusetts :bThe MIT Press,c1981.  ax, 477 p. 0aGeometryxStudy and teaching.@0000154706 0aComputer assisted instruction.@00001481531 aDiSessa, Andrea.@0000154707