@article{GDZPPN002203472,
title = {Normal projective degenerations of rational and ruled surfaces.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {372},
year = {1986},
pages = {76-89},
zbl = {0604.14020},
url = {http://dml.mathdoc.fr/item/GDZPPN002203472}
}
Badescu, Lucian. Normal projective degenerations of rational and ruled surfaces.. Journal für die reine und angewandte Mathematik, Tome 372 (1986) pp. 76-89. http://gdmltest.u-ga.fr/item/GDZPPN002203472/