P-tool - A Software Application for Choosing the Topology for Active Power Filters - Gurguiatu, Gelu; Bălănuță, Ciprian Daniel; Dușa, Alexandru; Roșu, Emil Mina; Munteanu, Toader (The Annals of “Dunarea de Jos“ University of Galati. Fascicle III, Electrotechnics, Electronics, Automatic Control, Informatics, 2018)