Jos C. M. Baeten Jan A. Bergstra Jan Willem Klop Decidability of Bisimulation Equivalence for Processes Generating Context-Free Languages. 94-111 1987 conf/parle/1987-2 PARLE (2) db/conf/parle/parle87-2.html#BaetenBK87 http://dx.doi.org/10.1007/3-540-17945-3_5