http://id.loc.gov/authorities/subjects/sh85042014 lcsh http://lemac.sgcb.mcu.es/Autoridades/LEMAC201211117/concept lemac http://lemag.sgcb.mcu.es/Autoridades/LEMAG201304205/concept lemag http://lemav.sgcb.mcu.es/Autoridades/LEMAV2015004440/concept lemav XX526748 LCSH; (Electric transformers) CSIC; (Transformadores eléctricos) TEST; (Transformers) Electricidad industrial: esquemas básicos José Roldán Viloria