Eric Berberich Efi Fogel Dan Halperin Kurt Mehlhorn Ron Wein Sweeping and Maintaining Two-Dimensional Arrangements on Surfaces: A First Step. 645-656 2007 conf/esa/2007 ESA http://dx.doi.org/10.1007/978-3-540-75520-3_57 db/conf/esa/esa2007.html#BerberichFHMW07