%0 Journal Article %A Boulanger, C. %A Schlitz, J. %T Nonlinear filtering with an infinite dimensional signal process. %J Portugaliae mathematica %D 1999 %P 345-359 %V 56 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/PORMA_1999__56_3_48661/ %G en %F PORMA_1999__56_3_48661