@article{GDZPPN002216388,
title = {Scheitels\"atze f\"ur Regelfl\"achen.},
journal = {Manuscripta mathematica},
volume = {4},
year = {1971},
pages = {309-322},
zbl = {0223.53010},
url = {http://dml.mathdoc.fr/item/GDZPPN002216388}
}
Hoschek, Josef. Scheitelsätze für Regelflächen.. Manuscripta mathematica, Tome 4 (1971) pp. 309-322. http://gdmltest.u-ga.fr/item/GDZPPN002216388/