@article{MO_2017_83_3_a3,
     author = {M. E. Stepanov},
     title = {Klein's {Erlangen} {Program} and geometry of a triangle},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {28--42},
     publisher = {mathdoc},
     volume = {83},
     number = {3},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2017_83_3_a3/}
}