Moshe Meyassed Robert H. Klenke James H. Aylor Resolving unknown inputs in mixed-level simulation with sequential elements. 1151-1164 1999 18 IEEE Trans. on CAD of Integrated Circuits and Systems 8 http://doi.ieeecomputersociety.org/10.1109/43.775634 db/journals/tcad/tcad18.html#MeyassedKA99