Ivan Titov James Henderson Paola Merlo Gabriele Musillo Online Graph Planarisation for Synchronous Parsing of Semantic and Syntactic Dependencies. 1562-1567 2009 IJCAI http://ijcai.org/papers09/Papers/IJCAI09-261.pdf conf/ijcai/2009 db/conf/ijcai/ijcai2009.html#TitovHMM09