@article{CMH_1956__31_139143,
     author = {Ernst Specker},
     title = {Teilmengen von {Mengen} mit {Relationen.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {302--314},
     publisher = {mathdoc},
     volume = {31},
     year = {1956},
     zbl = {0080.03703},
     url = {http://geodesic.mathdoc.fr/item/CMH_1956__31_139143/}
}