@article{JLT_2002_12_2_JLT_2002_12_2_a9,
     author = {M. H. Lee },
     title = {Casimir {Operators} on {Pseudodifferential} {Operators} of {Several} {Variables}},
     journal = {Journal of Lie theory},
     pages = {483--493},
     publisher = {mathdoc},
     volume = {12},
     number = {2},
     year = {2002},
     url = {http://geodesic.mathdoc.fr/item/JLT_2002_12_2_JLT_2002_12_2_a9/}
}