Andrzej Czygrinow Michal Hanckowiak Wojciech Wawrzyniak Fast Distributed Approximations in Planar Graphs. 78-92 2008 DISC http://dx.doi.org/10.1007/978-3-540-87779-0_6 conf/wdag/2008 db/conf/wdag/disc2008.html#CzygrinowHW08