Stina S. Bridgeman Giuseppe Di Battista Walter Didimo Giuseppe Liotta Roberto Tamassia Luca Vismara Turn-Regularity and Planar Orthogonal Drawings. 8-26 1999 conf/gd/1999 Graph Drawing http://link.springer.de/link/service/series/0558/bibs/1731/17310008.htm db/conf/gd/gd1999.html#BridgemanBDLTV99