@article{MS2_1975__36_166404,
     author = {Karsten Grove},
     title = {Involution-invariant geodesics.},
     journal = {Mathematica Scandinavica},
     pages = {98--109},
     publisher = {mathdoc},
     volume = {36},
     year = {1975},
     zbl = {0297.58006},
     url = {http://geodesic.mathdoc.fr/item/MS2_1975__36_166404/}
}