%0 Journal Article %A M. B. Karmanova %T Coarea formula for functions on 2-step Carnot groups with sub-Lorentzian structure %J Doklady Rossijskoj akademii nauk. Matematika, informatika, processy upravleniâ %D 2020 %P 61-64 %V 491 %I mathdoc %U http://geodesic.mathdoc.fr/item/DANMA_2020_491_a11/ %G ru %F DANMA_2020_491_a11