add automata refs

[tortinator]

ADD

@article{demri06,
	author = {Demri, Stephane},
	year = {2006},
	month = {01},
	pages = {311-348},
	title = {Linear-Time temporal logics with presburger constraints: An overview},
	volume = {16},
	journal = {Journal of Applied Non-Classical Logics},
	doi = {10.3166/jancl.16.311-347}
}

@article{DD07,
	title = "An automata-theoretic approach to constraint LTL",
	journal = "Information and Computation",
	volume = "205",
	number = "3",
	pages = "380 - 415",
	year = "2007",
	issn = "0890-5401",
	author = "Stéphane Demri and Deepak D’Souza",
}