00727nam a22002057a 4500999001500000001000600015003000900021005001700030008004100047040002800088082001900116100001800135245010800153260003800261300004100299650002800340700002400368942001200392952011700404  c7497d749721115BD-DhUAP20210123143845.0201103s1977    ii            000 0 eng d  aDLCcDLCdBD-DhUAPbEng00a515.35 ELS223  aElsgolts, L. 10aDifferential equations and the calculus of variations /cL. Elsgolts ; translated by George Yankovosky.  aMoscow :bMir publishers,cc1977.  a440 pages :billustrations ;c22 cm. 0aDifferential equations.  aYankovosky, George.  2ddccBK  00102ddc4070aUAPCLbUAPCLcGeneral Stacksd2021-01-23o515.35 ELSp3010021115r2021-01-23t1w2021-01-23yBK