@article{SIGMA_2018_14_a40,
     author = {Sarah B. Lobb and Frank W. Nijhoff},
     title = {A {Variational} {Principle} for {Discrete} {Integrable} {Systems}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2018},
     volume = {14},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2018_14_a40/}
}