LEBESGUE, Leçons sur l'intégration, 1904

First edition.
Henri Lebesgue (1875-1941), is one of the great French mathematicians of the first half of the twentieth century. He is recognized for his theory of integration and for his theory of measurement, which extends the important early work of Émile Borel.

His lessons on integration repeat the courses given in 1902-1903 at the Collège de France. He notably exhibited there what would become Lebesgue's complete works.