M. Łosiński, J. Klucznik. “Performance Analysis of Power Swing Blocking Feature in ABB 670 Series Impedance Relays”. Acta Energetica, no. 04 (December 31, 2012): 75–95. Accessed September 21, 2025. https://www.actaenergetica.org/index.php/journal/article/view/260.