@article{JRAM_1980__320_152299,
     author = {F.P. Cass and R. Trautner},
     title = {On relations between strong and ordinary summability.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {137--141},
     publisher = {mathdoc},
     volume = {320},
     year = {1980},
     zbl = {0478.40007},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1980__320_152299/}
}