@article{JOLT_2009_19_1_a6,
     author = {P. B\"acklund},
     title = {Families of {Equivariant} {Differential} {Operators} and {Anti-de} {Sitter} {Spaces}},
     journal = {Journal of Lie Theory},
     pages = {149--183},
     year = {2009},
     volume = {19},
     number = {1},
     zbl = {1186.58018},
     url = {http://geodesic.mathdoc.fr/item/JOLT_2009_19_1_a6/}
}