00309nam a2200109 a 450000500170000010000230001724500320004026000370007230000270010949000280013663000350016420251202164317.0  aPontryjagin, Lev S  aLearning higher mathematics  aNew YorkbSpringer Verlagc1984p  aviii,302 p.b22cm.cHB  aProblems in Mathematics  aMathematics:Higher Mathematics