@article{EUG_1991__28_a12, author = {Paul Halmos}, title = {H \ensuremath{\delta}\ensuremath{\iota}\ensuremath{\alpha}\ensuremath{\delta}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\alpha}\ensuremath{\sigma}\ensuremath{\acute\iota}\ensuremath{\alpha} \ensuremath{\lambda}\ensuremath{\acute\upsilon}\ensuremath{\sigma}\ensuremath{\eta}\ensuremath{\varsigma} {M\ensuremath{\alpha}\ensuremath{\theta}\ensuremath{\eta}\ensuremath{\mu}\ensuremath{\alpha}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\omega}\ensuremath{\nu}} \ensuremath{\pi}\ensuremath{\rho}o\ensuremath{\beta}\ensuremath{\lambda}\ensuremath{\eta}\ensuremath{\mu}\ensuremath{\acute\alpha}\ensuremath{\tau}\ensuremath{\omega}\ensuremath{\nu}.}, journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\Gamma} }, pages = {12-21}, publisher = {mathdoc}, volume = {28}, year = {1991}, language = {gr}, url = {http://geodesic.mathdoc.fr/item/EUG_1991__28_a12/} }