• Requirements for coordinated ancillary services covering different voltage levelsUebermasser, Stefan; Groiss, Christoph; Einfalt, Alfred; Thie, Nicolas; Vasconcelos, Maria; Helguero Cruz, Jorge Luis; Laaksonen, Hannu; Hovila, PetriCIRED, Open Access Proceeding Journal2017 / p. 1421-1424 : ill https://doi.org/10.1049/oap-cired.2017.1033