@article{JLT_2009_19_1_JLT_2009_19_1_a6,
     author = {P. B�cklund },
     title = {Families of {Equivariant} {Differential} {Operators} and {Anti-de} {Sitter} {Spaces}},
     journal = {Journal of Lie theory},
     pages = {149--183},
     publisher = {mathdoc},
     volume = {19},
     number = {1},
     year = {2009},
     url = {http://geodesic.mathdoc.fr/item/JLT_2009_19_1_JLT_2009_19_1_a6/}
}