@article{05529368,
title = {Cubic ruled surfaces with constant distribution parameter in },
journal = {Beitr\"age zur Algebra und Geometrie},
volume = {50},
year = {2009},
pages = {259-269},
zbl = {1162.53006},
language = {en},
url = {http://dml.mathdoc.fr/item/05529368}
}
Röschel, Otto. Cubic ruled surfaces with constant distribution parameter in . Beiträge zur Algebra und Geometrie, Tome 50 (2009) pp. 259-269. http://gdmltest.u-ga.fr/item/05529368/