# Air drilling (Petroleum engineering) { "id": "S85002628", "title": "Air drilling (Petroleum engineering)", "url": "/topics/S85002628", "kind": "topic-directory", "aeo_cohort": "topic-directory", "provider": "lcsh", "revision": "dc5fb3f20a50fbe9", "catalogue_revision": "f050b5d4780b1289", "numeric_address": "290486574016235072", "address_version": "morton4x16-v1", "coordinates": [ 0, 20, 17446, 4096 ], "answer_status": "Directory metadata; local answer requires separate source review", "truth_status": "Subject descriptor, not a factual answer or a demonstrated knowledge gap" } Directory metadata is not a factual answer or evidence of a global knowledge gap. Source: https://id.loc.gov/authorities/subjects/sh85002628 No owner-reviewed local answer yet.