@article{1183528787,
author = {Retherford, J. R.},
title = {On \v Ceby\v sev subspaces and unconditional bases in Banach spaces},
journal = {Bull. Amer. Math. Soc.},
volume = {73},
number = {6},
year = {1967},
pages = { 238-241},
language = {en},
url = {http://dml.mathdoc.fr/item/1183528787}
}
Retherford, J. R. On Čebyšev subspaces and unconditional bases in Banach spaces. Bull. Amer. Math. Soc., Tome 73 (1967) no. 6, pp. 238-241. http://gdmltest.u-ga.fr/item/1183528787/