@article{10_4153_CJM_1967_086_8,
     author = {Val, Patrick du},
     title = {Rational {Surfaces} with {Exceptional} {Unodes}},
     journal = {Canadian journal of mathematics},
     pages = {938--951},
     year = {1967},
     volume = {19},
     number = {1},
     doi = {10.4153/CJM-1967-086-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1967-086-8/}
}