Didier Galmiche Dominique Larchey-Wendling Structural Sharing and Efficient Proof-Search in Propositional Intuitionistic Logic. 101-112 1999 conf/asian/1999 ASIAN http://link.springer.de/link/service/series/0558/bibs/1742/17420101.htm db/conf/asian/asian99.html#GalmicheL99