@article{DCG_1986__1_130981,
     author = {K. Kedem and Ron Livne and J\'anos Pach and Micha Sharir},
     title = {On the {Union} of {Jordan} {Regions} and {Collision-Free} {Translational} {Motion} {Amidst} {Polygonal} {Obstacles.}},
     journal = {Discrete & computational geometry},
     pages = {59--72},
     publisher = {mathdoc},
     volume = {1},
     year = {1986},
     zbl = {0594.52004},
     url = {http://geodesic.mathdoc.fr/item/DCG_1986__1_130981/}
}