<?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://AATesaurus.cultura.gencat.cat/aat/getty_en">gravity heating</topic></authority><related type="broader"><topic>warm air heating</topic></related><variant type="other"><topic>gravity heating systems</topic></variant><variant type="other"><topic>gravity warm air heating</topic></variant><variant type="other"><topic>gravity warm air systems</topic></variant><variant type="other"><topic>gravity warm-air heating</topic></variant><variant type="other"><topic>gravity warm-air heating systems</topic></variant><variant type="other"><topic>gravity warm-air systems</topic></variant><variant type="other"><topic>heating systems, gravity warm-air</topic></variant><variant type="other"><topic>heating, gravity</topic></variant><variant type="other"><topic>heating, gravity warm-air</topic></variant><variant type="other"><topic>systems, gravity heating</topic></variant><variant type="other"><topic>systems, gravity warm air</topic></variant><variant type="other"><topic>systems, gravity warm-air</topic></variant><variant type="other"><topic>systems, gravity warm-air heating</topic></variant><variant type="other"><topic>warm air systems, gravity</topic></variant><variant type="other"><topic>warm-air heating systems, gravity</topic></variant> <note xml:lang="en"><![CDATA[ Central warm-air heating systems through which air is circulated by gravity. ]]></note></mads>