@article{MAN_1949__121_160172,
     author = {Ren\'ee Peiffer},
     title = {\"Uber {Identit\"aten} zwischen {Relationen.}},
     journal = {Mathematische Annalen},
     pages = {67--99},
     publisher = {mathdoc},
     volume = {121},
     year = {1949},
     zbl = {0040.15002},
     url = {http://geodesic.mathdoc.fr/item/MAN_1949__121_160172/}
}