@article{CM_1940__7__135_0,
     author = {Kober, H.},
     title = {A theorem on {Banach} spaces},
     journal = {Compositio Mathematica},
     pages = {135--140},
     publisher = {Johnson Reprint Corporation},
     volume = {7},
     year = {1940},
     zbl = {0022.05401},
     language = {en},
     url = {http://www.numdam.org/item/CM_1940__7__135_0/}
}