%0 Journal Article %A Durrett, Richard T. %T On the unboundedness of martingale transforms %J Séminaire de probabilités de Strasbourg %D 1985 %P 27-36 %V 19 %I Springer - Lecture Notes in Mathematics %U http://www.numdam.org/item/SPS_1985__19__27_0/ %G en %F SPS_1985__19__27_0