00445nam a2200157Ia 450000500170000000800460001703700120006304000200007504100130009508400190010810000210012724500550014826000620020330000100026554600120027520250508165740.0008  250505s9999    xx            000 0 eng d  aTextual  aFEDLbengcFEDL  aeng2eng  a510, FREqFEDL  afreudenthal Hans 0aDidactical phenomenology of mathematical structure  aHolland, Netherlands bD. Rediel Publishing Companyc1983  a585p.  aC.S.E.C