@article{10_1090_S0894_0347_07_00550_4,
     author = {Smania, Daniel},
     title = {Puzzle geometry and rigidity: {The} {Fibonacci} cycle is hyperbolic},
     journal = {Journal of the American Mathematical Society},
     pages = {629--673},
     publisher = {mathdoc},
     volume = {20},
     number = {3},
     year = {2007},
     doi = {10.1090/S0894-0347-07-00550-4},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-07-00550-4/}
}