@article{CMH_1954__28_139088,
     author = {B. Eckmann},
     title = {R\"aume mit {Mittelbildungen.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {329--340},
     publisher = {mathdoc},
     volume = {28},
     year = {1954},
     zbl = {0056.16403},
     url = {http://geodesic.mathdoc.fr/item/CMH_1954__28_139088/}
}