<?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/">Tubos</topic></authority><related type="narrower"><topic>Tubos de cobre</topic></related><related type="narrower"><topic>Tubos de hormigón</topic></related><related type="narrower"><topic>Tubos de plástico</topic></related><related type="narrower"><topic>Tubos de acero</topic></related><related type="other"><topic>Tuberías</topic></related><related type="other"><topic>Fontanería</topic></related><related type="other"><topic>Válvulas</topic></related><related type="other"><topic>Grifería</topic></related><variant type="other"><topic>Cañerías</topic></variant></mads>