@article{01336346,
title = {Contacting helicoidal surfaces with helix edges. (Ber\"uhrende Schraubfl\"achen mit Schraublinienkanten.)},
journal = {Mathematica Pannonica},
volume = {8},
year = {1997},
pages = {225-236},
zbl = {0923.53008},
language = {en},
url = {http://dml.mathdoc.fr/item/01336346}
}
Bär, Gert. Contacting helicoidal surfaces with helix edges. (Berührende Schraubflächen mit Schraublinienkanten.). Mathematica Pannonica, Tome 8 (1997) pp. 225-236. http://gdmltest.u-ga.fr/item/01336346/