@article{MZ_1971__122_171612,
     author = {Peter Hess},
     title = {On a {Method} of {Singular} {Perturbation} {Type} for {Proving} the {Solvability} of {Nonlinear} {Functional} {Equations} in {Banach} {Spaces.}},
     journal = {Mathematische Zeitschrift},
     pages = {355--362},
     publisher = {mathdoc},
     volume = {122},
     year = {1971},
     zbl = {0216.13202},
     url = {http://geodesic.mathdoc.fr/item/MZ_1971__122_171612/}
}