@article{MT_2012_15_2_a0,
     author = {S. G. Basalaev},
     title = {Parametrizations of level surfaces of real-valued mappings of {Carnot} groups},
     journal = {Matemati\v{c}eskie trudy},
     pages = {3--29},
     publisher = {mathdoc},
     volume = {15},
     number = {2},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MT_2012_15_2_a0/}
}