@article{KUKZ_1976_13_13_a28,
     author = {N. D. Yakimov},
     title = {Variational theorems for problems with depression curves},
     journal = {Trudy seminara po kraevym zada\v{c}am},
     pages = {258--275},
     publisher = {mathdoc},
     volume = {13},
     number = {13},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUKZ_1976_13_13_a28/}
}