BOUTROUX, Leçons sur les fonctions définies, 1908

Pierre Boutroux (1880-1922) was a French mathematician, lecturer at the Faculty of Sciences of Montpellier. His Leçons sur les fonctions définies par les équations différentielles du premier ordre (Lessons on Functions Defined by First-Order Differential Equations), based on his lectures at the Collège de France and supplemented by a note from Paul Painlevé, constitutes an important work on the qualitative theory of differential equations.