Glencora Borradaile Philip N. Klein An <i>O</i>(<i>n</i> log <i>n</i>) algorithm for maximum <i>st</i>-flow in a directed planar graph. 2009 56 J. ACM 2 http://doi.acm.org/10.1145/1502793.1502798 db/journals/jacm/jacm56.html#BorradaileK09