Andrew W. Mellon Foundation — Wikipedia: https://en.wikipedia.org/wiki/Andrew_W._Mellon_Foundation

Note: The source text directly confirms that the Andrew W. Mellon Foundation has a Wikipedia article. The Wikidata record includes a 'Wikimedia import URL' field that points to the English Wikipedia article about the Andrew W. Mellon Foundation, which matches the claimed URL structure (https://en.wikipedia.org/wiki/Andrew_W._Mellon_Foundation). The source explicitly documents this connection between the Wikidata entity and the Wikipedia article.