Brauer, Fred . The Qualitative Theory of Ordinary Differential Equations: An Introduction / Textual Documents Fred Brauer & John A. Nohel. - 1st ed. / - New york : Dover Publications , 1969. - iv, 314p. ; 21cm. Bib, Index ISBN: 0-486-65846-5 Subjects--Index Terms: Mathematics Differential Equations PG-Mathematics Dewey Class. No.: 515.3 / Br 72 Qu