@article{TMF_2008_154_2_a5,
     author = {V. A. Golovko and I. S. Krasil'shchik and A. M. Verbovetsky},
     title = {Variational {Poisson--Nijenhuis} structures for partial differential
},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {268--282},
     publisher = {mathdoc},
     volume = {154},
     number = {2},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_2008_154_2_a5/}
}