@ARTICLE {
	AUTHOR = "Pablo Barcel{\'o} and Leonid Libkin and Juan Reutter",
	TITLE ="Parameterized Regular Expressions and Their Languages",
	JOURNAL = "Theoretical Computer Science (TCS)",
	VOLUME = "474",
	PAGES = "21-45",
	MONTH = "Feb",
	YEAR = "2013",
	PUBLISHER = "Elsevier Science",
	ADDRESS = "Amsterdam, The Netherlands",
	ISSN = "0304-3975"
	}