@article{10_1155_S1024123X01001752,
     author = {Agarwal, Ravi P. and O'Regan, Donal and Lakshmikantham, V.},
     title = {Existence criteria for singular initial value problems with sign changing nonlinearities.},
     journal = {Mathematical Problems in Engineering},
     pages = {503},
     publisher = {mathdoc},
     volume = {7},
     number = {6},
     year = {2001},
     doi = {10.1155/S1024123X01001752},
     zbl = {1023.34001},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/articles/10.1155/S1024123X01001752/}
}