@article{JLT_2002_12_1_JLT_2002_12_1_a11,
     author = {E. G. F. Thomas},
     title = {An {Invariant} {Symmetric} {Non-Selfadjoint} {Differential} {Operator}},
     journal = {Journal of Lie theory},
     pages = {245--257},
     year = {2002},
     volume = {12},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/JLT_2002_12_1_JLT_2002_12_1_a11/}
}