Ordinary differential equations.
Pontryagin, L.S.\
Ordinary differential equations. - - Addison-Wesley, Reading, Mass., 1962 - p.vi,298,illus.,23cm., - .
6
517.91 Pon-2
Ordinary differential equations. - - Addison-Wesley, Reading, Mass., 1962 - p.vi,298,illus.,23cm., - .
6
517.91 Pon-2