@article{MAN_1996__306_3_165443,
     author = {R.V. Gurjar and D.-Q. Zhang},
     title = {On the fundamental groups of some open rational surfaces.},
     journal = {Mathematische Annalen},
     pages = {15--30},
     year = {1996},
     volume = {306},
     number = {3},
     zbl = {0853.14010},
     url = {http://geodesic.mathdoc.fr/item/MAN_1996__306_3_165443/}
}