de pfaffs

GOURSAT ON PFAFFS PROBLEM

https://www.ams.org/journals/bull/1924-30-07/S0002-9904-1924-03903-2/S0002-9904-1924-03903-2.pdf

GOURSAT ON PFAFFS PROBLEM. Leçons sur le Problème de Pfaff. By Edouard Goursat, Paris, J. Her- mann, 1922. 386 pp. On the first page of Volume 3 of ...