@inproceedings\{bdg-mupsepd-07
, author =	"Carla Binucci and Walter Didimo and Francesco Giordano"
, title =	"Maximum Upward Planar Subgraphs of Embedded Planar Digraphs"
, series =	"Lecture Notes in Computer Science"
, volume =	4875
, booktitle =	"Proceedings of 15th International Symposium on Graph Drawing (GD 2007)"
, editor =	"Seok-Hee Hong and Takao Nishizeki and Wu Quan"
, pages =	"195-206"
, year =	2008
}