@article{MZM_2005_78_2_a6,
     author = {M. Deza and M. I. Shtogrin},
     title = {A metric of constant curvature on polycycles},
     journal = {Matemati\v{c}eskie zametki},
     pages = {223--233},
     publisher = {mathdoc},
     volume = {78},
     number = {2},
     year = {2005},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2005_78_2_a6/}
}