@article{ZNSL_2008_353_a4,
     author = {V. A. Zapol'skii},
     title = {Functional characterization of {Vasil'ev} invariants},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {39--53},
     publisher = {mathdoc},
     volume = {353},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2008_353_a4/}
}