@article{AM2_1976__14_136587,
     author = {Wolfgang Walter},
     title = {On the functional equation of {Bellman} in the theory of dynamic programming. {(Short} {Communication).}},
     journal = {Aequationes mathematicae},
     pages = {247--248},
     year = {1976},
     volume = {14},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AM2_1976__14_136587/}
}