@article{JEMS_2006_8_1_a4,
     author = {Graziano Crasta},
     title = {A symmetry problem in the calculus of variations},
     journal = {Journal of the European Mathematical Society},
     pages = {139--154},
     publisher = {mathdoc},
     volume = {8},
     number = {1},
     year = {2006},
     doi = {10.4171/jems/41},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/41/}
}