Giusi Castiglione Antonio Restivo Marinella Sciortino Hopcroft's Algorithm and Cyclic Automata. 172-183 2008 LATA http://dx.doi.org/10.1007/978-3-540-88282-4_17 conf/lata/2008 db/conf/lata/lata2008.html#CastiglioneRS08