@article{SIGMA_2007_3_a1,
     author = {S. Sahi},
     title = {Raising and {Lowering} {Operators} for {Askey{\textendash}Wilson} {Polynomials}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2007},
     volume = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2007_3_a1/}
}