@article{2828, author = {Derrick, W.R.}, title = {Nonlinear functional Sturm-Liouville equations}, journal = {Portugaliae mathematica}, volume = {36}, year = {1977}, pages = {227-237}, zbl = {0451.34018}, mrnumber = {0597844}, language = {en}, url = {http://dml.mathdoc.fr/item/2828} }
Derrick, W.R. Nonlinear functional Sturm-Liouville equations. Portugaliae mathematica, Tome 36 (1977) pp. 227-237. http://gdmltest.u-ga.fr/item/2828/