Ferrite cores - Guidelines on dimensions and the limits of surface irregularities - Part 7: EER-cores (IEC 63093-7:2018); German version EN IEC 63093-7:2018— 21 стр.
Ferrite cores - Guidelines on the limits of surface irregularities - Part 1: General specification (IEC 60424-1:2015); German version EN 60424-1:2016— 13 стр.