%0 Journal Article %A Piotr Besala %T Observations on quasi-linear partial differential equations %J Annales Polonici Mathematici %D 1991 %P 267-283 %V 53 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/ap-53-3-267-283/ %R 10.4064/ap-53-3-267-283 %G en %F 10_4064_ap_53_3_267_283