@article{AIHPC_2006__23_6_877_0,
     author = {Ure\~na, Antonio J.},
     title = {Isolated periodic minima are unstable},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {877--889},
     publisher = {Elsevier},
     volume = {23},
     number = {6},
     year = {2006},
     doi = {10.1016/j.anihpc.2005.09.010},
     mrnumber = {2271699},
     zbl = {05138724},
     language = {en},
     url = {http://archive.numdam.org/articles/10.1016/j.anihpc.2005.09.010/}
}