Rajeev Alur Marcelo Arenas Pablo Barceló Kousha Etessami Neil Immerman Leonid Libkin First-Order and Temporal Logics for Nested Words. 2008 4 Logical Methods in Computer Science 4 http://dx.doi.org/10.2168/LMCS-4(4:11)2008 db/journals/lmcs/lmcs4.html#AlurABEIL08