@article{GT_2003_7_2_a1,
     author = {Ozsv\'ath, Peter and Szab\'o, Zolt\'an},
     title = {Knot {Floer} homology and the four-ball genus},
     journal = {Geometry & topology},
     pages = {615--639},
     publisher = {mathdoc},
     volume = {7},
     number = {2},
     year = {2003},
     doi = {10.2140/gt.2003.7.615},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/gt.2003.7.615/}
}