00346nam a2200109Ia 4500008004100000082001700041100001800058245006300076260003700139300001500176490004500191260312b        |||||||| |||| 00| 0 eng d  a514bG778.HT  aGray, Brayton  aHomotopy theoryb; an introduction to algebraic topology /  aNew York:bAcademic Press,c1975  axiv, 368p.  aPure and Applied Mathematics seriesv 64