Paolo Baldan Andrea Corradini Tobias Heindel Barbara König Pawel Sobocinski Unfolding Grammars in Adhesive Categories. 350-366 2009 CALCO http://dx.doi.org/10.1007/978-3-642-03741-2_24 conf/calco/2009 db/conf/calco/calco2009.html#BaldanCHKS09