@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

<https://bioregistry.io/pco:0000021> rdfs:seeAlso <http://purl.obolibrary.org/obo/PCO_0000021>,
        <https://bioportal.bioontology.org/ontologies/PCO/?p=classes&conceptid=http://purl.obolibrary.org/obo/PCO_0000021>,
        <https://www.ebi.ac.uk/ols4/ontologies/pco/terms?iri=http://purl.obolibrary.org/obo/PCO_0000021> .