http://AATesaurus.cultura.gencat.cat/aat/getty_enhttp://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31347532transit system elements http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31347532 transportation elements BT http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31347532 railroad junctions NT http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31347532 tracks and track components NT http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31347532 signal gantries NT http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31347532 elements, transit system UF http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31347532 transit system element UF