@article{TMF_2007_150_2_a4,
     author = {S. M. Klishevich},
     title = {Additional constraints on quasi-exactly solvable systems},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {237--248},
     publisher = {mathdoc},
     volume = {150},
     number = {2},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_2007_150_2_a4/}
}