# Schlieren methods (Optics) { "id": "S92004593", "title": "Schlieren methods (Optics)", "url": "/topics/S92004593", "kind": "topic-directory", "aeo_cohort": "topic-directory", "provider": "lcsh", "revision": "d30175dd9bceed49", "catalogue_revision": "f050b5d4780b1289", "numeric_address": "14717847438262141510", "address_version": "morton4x16-v1", "coordinates": [ 0, 21, 61315, 50176 ], "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/sh92004593 No owner-reviewed local answer yet.