@article{MZ_1971__119_171479,
     author = {Richard Holmes},
     title = {Smoothness {Indices} for {Convex} {Functions} and the {Unique} {Hahn-Banach} {Extension} {Problem.}},
     journal = {Mathematische Zeitschrift},
     pages = {95--110},
     publisher = {mathdoc},
     volume = {119},
     year = {1971},
     zbl = {0196.13605},
     url = {http://geodesic.mathdoc.fr/item/MZ_1971__119_171479/}
}