“…If it comes to electromagnetism, there are several "different" methods among scientists-for example see Bossavit (1988), Jiang (1998), Ciarlet Jr andZou (1999), Sadiku (2000), Hiptmair (2002), Bastos and Sadowski (2003), Monk (2003), (Demkowicz, 2006, Sect. 17), Gibson (2007), Li (2009), Gillette et al (2016), (Abali, 2016, Sect. 3)-and a consensus as to the "best" approach is yet missing. If one aims at solving electromagnetic fields E and B by satisfying Maxwell's equations, then FEM with standard elements cannot be used and there are various so-called mixed elements, see Arnold and Logg (2014), whose techniques are based on works of Raviart and Thomas (1977) and Nédélec (1980).…”