@article{MZM_2020_107_3_a0,
     author = {A. B. Antonevich and E. U. Leonova},
     title = {The {Extended} {Legendre} {Transform} and {Related} {Variational} {Principles}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {323--340},
     publisher = {mathdoc},
     volume = {107},
     number = {3},
     year = {2020},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2020_107_3_a0/}
}