Anton Batliner Anke Feldhaus Stefan Geißler Andreas Kießling Tibor Kiss Ralf Kompe Elmar Nöth Integrating Syntactic and Prosodic Information for the Efficient Detection of Empty Categories http://arxiv.org/abs/cmp-lg/9607004 1996 CoRR cmp-lg/9607004 db/journals/corr/corr9607.html#cmp-lg-9607004 informal publication