Martin Sauerhoff Ingo Wegener Ralph Werchner Optimal Ordered Binary Decision Diagrams for Tree-like Circuits Electronic Colloquium on Computational Complexity (ECCC) 1996 22 3 db/journals/eccc/eccc3.html#ECCC-TR96-022 http://eccc.hpi-web.de/eccc-reports/1996/TR96-022/index.html