@article{MZ_1993__212_4_174490,
     author = {E.M. Opdam},
     title = {An analogue of the {Gauss} summation formula for hypergeometric functions related to root systems.},
     journal = {Mathematische Zeitschrift},
     pages = {311--336},
     publisher = {mathdoc},
     volume = {212},
     number = {4},
     year = {1993},
     zbl = {0789.33009},
     url = {http://geodesic.mathdoc.fr/item/MZ_1993__212_4_174490/}
}