%0 Journal Article %A Z. A. Ivković %T An elementary property of conditional mathematical expectation. Application to the linear regularity of stochastic processes %J Matematički vesnik %D 1969 %P 331 %V 21 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/MV_1969_21_3_a10/ %F MV_1969_21_3_a10