00474nam a2200193 a 450000500170000000800410001703500190005810000210007722200310009824500280012930000100015736200230016765300160019065300130020665300160021990400150023590500130025099900170026320210219153453.0991125n 000 0 u aUPN01000101712 aHOWSON, Geoffrey aMT :bMATHEMATICS TEACHING aTeachers of mathematics a28-31 a1993 No. 142, mar.0 aENSEÑANZA0 aMAESTROS0 aMATEMATICAS aACb039523 aArticulo c77740d77740