Joachim Böttger Ulrik Brandes Oliver Deussen Hendrik Ziezold Map Warping for the Annotation of Metro Maps. 199-206 2008 PacificVis http://dx.doi.org/10.1109/PACIFICVIS.2008.4475477 conf/apvis/2008 db/conf/apvis/pacificvis2008.html#BottgerBDZ08