@article{MZ_1954__61_169447,
     author = {H.C. Gupta},
     title = {An operational relation.},
     journal = {Mathematische Zeitschrift},
     pages = {70--74},
     publisher = {mathdoc},
     volume = {61},
     year = {1954},
     zbl = {0057.05604},
     url = {http://geodesic.mathdoc.fr/item/MZ_1954__61_169447/}
}