%0 Journal Article
%A Ribeiro, Hugo
%T Just half a century ago...
%J Portugaliae mathematica
%D 1987
%P III-IV
%V 44
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/PORMA_1987__44_1_115564/
%F PORMA_1987__44_1_115564