@article{MZ_1994__216_4_174647,
     author = {Jens Heber},
     title = {On the geodesics flow of tori without conjugate points.},
     journal = {Mathematische Zeitschrift},
     pages = {209--216},
     publisher = {mathdoc},
     volume = {216},
     number = {4},
     year = {1994},
     zbl = {0807.53039},
     url = {http://geodesic.mathdoc.fr/item/MZ_1994__216_4_174647/}
}