BOULIGAND, Lignes de niveau, lignes intégrales, 1937

Georges Bouligand (1889-1979) was a French mathematician, known for his work in analysis, geometry, and topology. He was a professor at the Faculty of Sciences in Poitiers. This work, co-authored with Jacques Devisme, is a graphical and pedagogical introduction to the study of level lines and integral lines. It deals with differential equations and the topology of vector fields, which are key concepts in mathematics and physics.