@article{MZ_1950__52_169135,
     author = {TIETZE},
     title = {Die {Relation} zwischen den drei quadratischen {Fundamentalformen} einer {Fl\"ache}},
     journal = {Mathematische Zeitschrift},
     pages = {590--592},
     publisher = {mathdoc},
     volume = {52},
     year = {1950},
     zbl = {0035.23101},
     url = {http://geodesic.mathdoc.fr/item/MZ_1950__52_169135/}
}