Michael Moortgat Symmetries in Natural Language Syntax and Semantics: The Lambek-Grishin Calculus. 264-284 2007 conf/wollic/2007 WoLLIC http://dx.doi.org/10.1007/978-3-540-73445-1_19 db/conf/wollic/wollic2007.html#Moortgat07