@article{PDML_1982___4B_A14_0,
     author = {Pytlik, T.},
     title = {Radial {Convolutors} on {Free} {Groups}},
     journal = {Publications du D\'epartement de math\'ematiques (Lyon)},
     pages = {1--1},
     publisher = {Universit\'e Claude Bernard - Lyon 1},
     number = {4B},
     year = {1982},
     zbl = {0572.43002},
     language = {en},
     url = {http://www.numdam.org/item/PDML_1982___4B_A14_0/}
}