@article{FPM_2013_18_2_a2,
     author = {E. A. Zavalnyuk},
     title = {Steiner ratio for the {Hadamard} surfaces of curvature at most~$k<0$},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {35--51},
     publisher = {mathdoc},
     volume = {18},
     number = {2},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_2013_18_2_a2/}
}