@article{IM_1981__65_142840,
     author = {Ren\'e Michel},
     title = {Sur la rigidit\'e impos\'ee par la longeur des g\'eod\'esiques.},
     journal = {Inventiones mathematicae},
     pages = {71--84},
     publisher = {mathdoc},
     volume = {65},
     year = {1981},
     zbl = {0471.53030},
     url = {http://geodesic.mathdoc.fr/item/IM_1981__65_142840/}
}