<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://roble.intecca.uned.es/tematres/lem/">Metales de las tierras raras</topic></authority><related type="narrower"><topic>Cerio</topic></related><related type="narrower"><topic>Europio</topic></related><related type="narrower"><topic>Gadolinio</topic></related><related type="narrower"><topic>Neodimio</topic></related><related type="narrower"><topic>Samario</topic></related><related type="other"><topic>Tierras raras</topic></related><related type="broader"><topic>Metales no férreos</topic></related><variant type="other"><topic>Lantánidos</topic></variant></mads>