@article{VMP_2000_1_2_a2,
     author = {L. G. Beliovskaya and N. A. Bogomolov and A. D. Kovalev},
     title = {Construction of isoline maps of functions of two variables},
     journal = {Numerical methods and programming},
     pages = {15--23},
     publisher = {mathdoc},
     volume = {1},
     number = {2},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMP_2000_1_2_a2/}
}