@article{PORMA_1962__21_2_114885,
     author = {Davis, H.S. and Stadtlander, D.P. and Swingle, P.M.},
     title = {Properties of the set functions $T^n$},
     journal = {Portugaliae mathematica},
     pages = {113--133},
     publisher = {mathdoc},
     volume = {21},
     number = {2},
     year = {1962},
     mrnumber = {0142108},
     zbl = {0107.40101},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1962__21_2_114885/}
}