@article{EJDE_2012__2012__a14,
     author = {Verma,  Amit K.},
     title = {Monotone iterative method and regular singular nonlinear {BVP} in the presence of reverse ordered upper and lower solutions},
     journal = {Electronic journal of differential equations},
     year = {2012},
     volume = {2012},
     zbl = {1243.34022},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2012__2012__a14/}
}