Diego Calvanese Giuseppe De Giacomo Maurizio Lenzerini Moshe Y. Vardi An Automata-Theoretic Approach to Regular XPath. 18-35 2009 DBPL http://dx.doi.org/10.1007/978-3-642-03793-1_2 conf/dbpl/2009 db/conf/dbpl/dbpl2009.html#CalvaneseGLV09