@article{IM_1992__108_2_144006,
     author = {Herbert S. Wilf and Doron Zeilberger},
     title = {An algorithmic proof theory for hypergeometric (ordinary and },
     journal = {Inventiones mathematicae},
     pages = {575--634},
     publisher = {mathdoc},
     volume = {108},
     number = {2},
     year = {1992},
     zbl = {0739.05007},
     url = {http://geodesic.mathdoc.fr/item/IM_1992__108_2_144006/}
}