@article{VMP_2002_3_1_a7,
     author = {A. V. Skvortsov},
     title = {An algorithm for constructing the union, intersection and difference of},
     journal = {Numerical methods and programming},
     pages = {116--123},
     year = {2002},
     volume = {3},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMP_2002_3_1_a7/}
}