@article{DAN_1990_314_5_a2,
     author = {N. N. Vorobjov (Jr.) and D. Yu. Grigor'ev},
     title = {Determination of the number of connected components of a},
     journal = {Doklady Akademii Nauk},
     pages = {1040--1043},
     publisher = {mathdoc},
     volume = {314},
     number = {5},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1990_314_5_a2/}
}