@article{JRAM_1968__229_150839,
     author = {Robert L. Ellis},
     title = {The state of a bounded linear operator on a {non-Archimedian} normed space.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {155--162},
     publisher = {mathdoc},
     volume = {229},
     year = {1968},
     zbl = {0161.34402},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1968__229_150839/}
}