@article{MZ_1986__192_173749,
     author = {Ray Redheffer},
     title = {A {Classification} of {Solutions} of {Certain} {Nonlinear} {Differential} {Inequalities} with {Application} to {Theorems} of {Liouville} {Type.}},
     journal = {Mathematische Zeitschrift},
     pages = {453--466},
     publisher = {mathdoc},
     volume = {192},
     year = {1986},
     zbl = {0617.35137},
     url = {http://geodesic.mathdoc.fr/item/MZ_1986__192_173749/}
}