00267nam a22001097a 4500003000400000008004100004082001700045100001700062245003800079260003200117300000800149OSt231225b        |||||||| |||| 00| 0 eng d  a517.38bK26E  aKells, L. M.  aElementary differential equations  aMcgraw Hill Kogakushac1965  a430