General channel-routing algorithm
Malgorzata Marek-Sadowska, E.S. Kuh · IEE Proceedings G (Electronic Circuits and Systems) · 1983
A new approach to the 2-layer channel-routing problem is introduced. The method allows horizontal and vertical connections on both layers. An order graph similar to the traditional vertical constraint graph is used in the algorithm. The main advantage is that the method is general and is immune to cyclic constraints. Furthermore, the channel width does not have a lower bound equal to the maximum density.