@article{MAN_1968__175_161667,
     author = {R. RICHBERG},
     title = {Stetige streng pseupokonvexe {Funktionen.}},
     journal = {Mathematische Annalen},
     pages = {257--286},
     year = {1968},
     volume = {175},
     url = {http://geodesic.mathdoc.fr/item/MAN_1968__175_161667/}
}