@article{VMUMM_2013_6_a2,
     author = {A. A. Flerov},
     title = {Sets with not more than two-valued metric projection on planes},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {14--19},
     publisher = {mathdoc},
     number = {6},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2013_6_a2/}
}