@article{TMF_2015_184_1_a3, author = {V. G. Marikhin}, title = {Action as an~invariant of {B\"acklund} transformations for {Lagrangian} systems}, journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika}, pages = {71--78}, publisher = {mathdoc}, volume = {184}, number = {1}, year = {2015}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TMF_2015_184_1_a3/} }