@article{MAN_1973__203_162424,
     author = {Ryotaro Sato},
     title = {On the {Limit} of {Weighted} {Operator} {Averages.}},
     journal = {Mathematische Annalen},
     pages = {1--8},
     publisher = {mathdoc},
     volume = {203},
     year = {1973},
     zbl = {0243.47006},
     url = {http://geodesic.mathdoc.fr/item/MAN_1973__203_162424/}
}