@article{CMH_1969__44_139386,
     author = {E. Ogg},
     title = {Ein {Satz} \"uber orthogonal abgeschlossene {Unterr\"aume.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {117--119},
     publisher = {mathdoc},
     volume = {44},
     year = {1969},
     zbl = {0258.15014},
     url = {http://geodesic.mathdoc.fr/item/CMH_1969__44_139386/}
}