@article{10_21136_CPMF_1935_123567,
     author = {Fr\"ohlich, Walter},
     title = {Eine {Normalform} f\"ur {Viererz\"opfe}},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky a fysiky},
     pages = {177--179},
     publisher = {mathdoc},
     volume = {64},
     number = {6},
     year = {1935},
     doi = {10.21136/CPMF.1935.123567},
     language = {ge},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPMF.1935.123567/}
}