@article{MZ_1943__49_169047,
     author = {P. Lorenzen},
     title = {Eine {Bemerkung} zum {Schreierschen} {Verfeinerungssatz}},
     journal = {Mathematische Zeitschrift},
     pages = {647--653},
     publisher = {mathdoc},
     volume = {49},
     year = {1943},
     zbl = {0060.05907},
     url = {http://geodesic.mathdoc.fr/item/MZ_1943__49_169047/}
}