00340nam a2200121Ia 4500082001700000100002000017245005100037260005200088300001500140490005300155500000500208700000500213  a514bN147.HI  aNagano, Tadashi  aHomotopy invariants in differential geometryb  aProvidencebAmerican Mathematical Societyc1970  a41p. Bibl.  aAmerican Mathematical Society memoirs v no. 100  a  a