Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{PORMA_1977__36_3-4_115318, author = {Derrick, W.R.}, title = {Nonlinear functional {Sturm-Liouville} equations}, journal = {Portugaliae mathematica}, pages = {227--237}, publisher = {mathdoc}, volume = {36}, number = {3-4}, year = {1977}, mrnumber = {0597844}, zbl = {0451.34018}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PORMA_1977__36_3-4_115318/} }
Derrick, W.R. Nonlinear functional Sturm-Liouville equations. Portugaliae mathematica, Tome 36 (1977) no. 3-4, pp. 227-237. http://geodesic.mathdoc.fr/item/PORMA_1977__36_3-4_115318/