@article{TMF_2009_159_1_a8,
     author = {M. Sebawe Abdalla and P. G. L. Leach},
     title = {Lie algebraic treatment of the~quadratic invariants for a~quantum system},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {142--161},
     publisher = {mathdoc},
     volume = {159},
     number = {1},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_2009_159_1_a8/}
}