@article{Habets_Gaudenzi_1999, title={Existence and multiplicity of positive solutions for boundary value problems of 2d order ODE}, volume={14}, url={https://apcz.umk.pl/TMNA/article/view/TMNA.1999.024}, abstractNote={We study the existence and multiplicity of positive solutions of the boundary value problem $$ uā€™ā€™+sf(t,u)=0,\quad u(0)=u(1)=0, $$ where $s$ is a positive parameter and $f$ is a non-negative function. We indicate examples with more than two solutions.}, number={1}, journal={Topological Methods in Nonlinear Analysis}, author={Habets, Patrick and Gaudenzi, Marcellino}, year={1999}, month={Sep.}, pages={131ā€“150} }