Glencora Borradaile Philip N. Klein Shay Mozes Yahav Nussbaum Christian Wulff-Nilsen Multiple-Source Multiple-Sink Maximum Flow in Directed Planar Graphs in Near-Linear Time. 170-179 2011 FOCS http://dx.doi.org/10.1109/FOCS.2011.73 conf/focs/2011 db/conf/focs/focs2011.html#BorradaileKMNW11