@article {2008,
	title = {Multiple bound states for the Schroedinger-Poisson problem},
	journal = {Commun. Contemp. Math. 10 (2008) 391-404},
	year = {2008},
	doi = {10.1142/S021919970800282X},
	url = {http://hdl.handle.net/1963/2679},
	author = {Antonio Ambrosetti and David Ruiz}
}
