Contribution to the theory of certain non-linear differential equations
by Rui Pacheco de Figueiredo.
Lisboa : Junta de Investigações do Ultramar, 1960.
125 págs. ; 25 cm.
Serie: Estudos, ensaios e documentos ; 73
Complements an earlier paper in Annals of Mathematics Studies, no. 45.
Reseña: MathSciNet, 25 #2291