@article{SPS_1985__19__27_0,
     author = {Durrett, Richard T.},
     title = {On the unboundedness of martingale transforms},
     journal = {S\'eminaire de probabilit\'es de Strasbourg},
     pages = {27--36},
     publisher = {Springer - Lecture Notes in Mathematics},
     volume = {19},
     year = {1985},
     mrnumber = {889466},
     zbl = {0557.60034},
     language = {en},
     url = {http://www.numdam.org/item/SPS_1985__19__27_0/}
}