%0 Journal Article %A C.D. Sogge %A F.M. Christ %T The weak type L1 convergence of eigenfunction expansions for pseudodifferential operators. %J Inventiones mathematicae %D 1988 %P 421-454 %V 94 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM_1988__94_2_143632/ %F IM_1988__94_2_143632