@article{ZVMMF_1980_20_2_a1,
     author = {\`E. I. Volynskii and S. I. Kas'yanenko and M. Z. Khenkin},
     title = {A method of weakening the constraints in constrained extremum problems},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {289--297},
     publisher = {mathdoc},
     volume = {20},
     number = {2},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1980_20_2_a1/}
}