@article{RM_1999_54_6_a13,
     author = {A. W. Niukkanen},
     title = {A method of factorization and special transformations for the {Appell} function $F_4$ and the {Horn} functions $H_1$ and~$G_2$},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {1254--1256},
     year = {1999},
     volume = {54},
     number = {6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1999_54_6_a13/}
}