@article{1077304281,
author = {Harbourne, Brian},
title = {Blowings-up of $\mathbf{P}^2$
and their blowings-down},
journal = {Duke Math. J.},
volume = {52},
number = {1},
year = {1985},
pages = { 129-148},
language = {en},
url = {http://dml.mathdoc.fr/item/1077304281}
}
Harbourne, Brian. Blowings-up of $\mathbf{P}^2$
and their blowings-down. Duke Math. J., Tome 52 (1985) no. 1, pp. 129-148. http://gdmltest.u-ga.fr/item/1077304281/