Dinesh Bhatia Amit Chowdhary Spyros Tragoudas Mathematical model for routability analysis of FPGAs. 76-79 1994 Great Lakes Symposium on VLSI https://doi.org/10.1109/GLSV.1994.289992 conf/glvlsi/1994 db/conf/glvlsi/glvlsi1994.html#BhatiaCT94