{"id":"S85110902","label":"Railroad tunnels--Ventilation","description":"","source_url":"https://id.loc.gov/authorities/subjects/sh85110902","normalized_label":"railroad tunnels--ventilation","broader":["http://id.loc.gov/authorities/subjects/sh85142747"],"aliases":[],"source_identifier":"http://id.loc.gov/authorities/subjects/sh85110902","provider":"lcsh","revision":"8ac5b1c19d166312","taxonomy_revision":"f050b5d4780b1289","title":"Railroad tunnels--Ventilation","url":"/topics/S85110902","kind":"topic-directory","aeo_cohort":"topic-directory","catalogue_revision":"f050b5d4780b1289","numeric_address":"10090526347375018500","address_version":"morton4x16-v1","coordinates":[0,20,19137,55296],"answer_status":"Directory metadata; local answer requires separate source review","truth_status":"Subject descriptor, not a factual answer or a demonstrated knowledge gap","reviewed_answer":null}