%0 Journal Article %A Varopoulos, Nicolas Th. %T A theorem on weak type estimates for Riesz transforms and martingale transforms %J Annales de l'Institut Fourier %D 1981 %P 257-264 %V 31 %N 1 %I Institut Fourier %C Grenoble %U http://archive.numdam.org/articles/10.5802/aif.826/ %R 10.5802/aif.826 %G en %F AIF_1981__31_1_257_0