@article{MAN_1994__300_2_165253,
     author = {Francois Lalonde},
     title = {Isotopy of sympletic balls, {Gromov'} s radius and the structure of ruled symplectic 4-manifolds.},
     journal = {Mathematische Annalen},
     pages = {273--296},
     publisher = {mathdoc},
     volume = {300},
     number = {2},
     year = {1994},
     zbl = {0812.53032},
     url = {http://geodesic.mathdoc.fr/item/MAN_1994__300_2_165253/}
}