@article{MAN_1957__133_160547,
     author = {R.M. Redheffer},
     title = {The {Riccati} {Equation:} {Initial} {Values} and {Inequalities.}},
     journal = {Mathematische Annalen},
     pages = {235--250},
     publisher = {mathdoc},
     volume = {133},
     year = {1957},
     zbl = {0102.07201},
     url = {http://geodesic.mathdoc.fr/item/MAN_1957__133_160547/}
}