@article{SM_2015_206_5_a5,
     author = {I. V. Sypchenko and D. S. Timonina},
     title = {Closed geodesics on piecewise smooth surfaces of revolution with constant curvature},
     journal = {Sbornik. Mathematics},
     pages = {738--769},
     year = {2015},
     volume = {206},
     number = {5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2015_206_5_a5/}
}