@article{MZM_2017_102_2_a7,
     author = {A. V. Maslei},
     title = {Gehring--Martin--Tan {Numbers} and {Tan} {Numbers} of {Elementary} {Subgroups} of~$\operatorname{PSL}(2,\mathbb{C})$},
     journal = {Matemati\v{c}eskie zametki},
     pages = {255--269},
     publisher = {mathdoc},
     volume = {102},
     number = {2},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2017_102_2_a7/}
}