@article{MAN_1964__154_161173,
     author = {O. NJ\"ASTAD},
     title = {On {Real-valued} {Proximity} {Mappings.}},
     journal = {Mathematische Annalen},
     pages = {413--419},
     publisher = {mathdoc},
     volume = {154},
     year = {1964},
     url = {http://geodesic.mathdoc.fr/item/MAN_1964__154_161173/}
}