@article {1998,
	title = {Branching points for a class of variational operators},
	journal = {J. Anal. Math.  76 (1998) 321-335},
	year = {1998},
	publisher = {Springer},
	doi = {10.1007/BF02786940},
	url = {http://hdl.handle.net/1963/3314},
	author = {Antonio Ambrosetti}
}
