@article{MAN_1971__191_162119,
     author = {M. VALDIVIA},
     title = {On {D} {F}  {Spaces.}},
     journal = {Mathematische Annalen},
     pages = {38--43},
     publisher = {mathdoc},
     volume = {191},
     year = {1971},
     url = {http://geodesic.mathdoc.fr/item/MAN_1971__191_162119/}
}