@article{DAN_1992_325_2_a0,
     author = {I. M. Gel'fand and M. I. Graev and V. S. Retakh},
     title = {Difference analogues and $q$-analogues of general hypergeometric},
     journal = {Doklady Akademii Nauk},
     pages = {215--220},
     publisher = {mathdoc},
     volume = {325},
     number = {2},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1992_325_2_a0/}
}