@article{MZM_2002_72_5_a13,
     author = {A. M. Popov},
     title = {Inverse {Problem} of the {Calculus} of {Variations} for {Systems} of {Differential-Difference} {Equations} of {Second} {Order}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {745--749},
     publisher = {mathdoc},
     volume = {72},
     number = {5},
     year = {2002},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2002_72_5_a13/}
}