"elsgolts, l . "
differential equations and the calculus of variations: / l.. elsgolts - 1 ed. - ussr : mir 1970. - ", 440p.; 22 cm."
hard cover
517. 38 els
differential equations and the calculus of variations: / l.. elsgolts - 1 ed. - ussr : mir 1970. - ", 440p.; 22 cm."
hard cover
517. 38 els