Error: Could not fetch URL - HTTPSConnectionPool(host='web.archive.org', port=443): Max retries exceeded with url: /web/20190303134817/http://pdfs.semanticscholar.org/b67b/b9f54c0e79bc73c8b205304a2f0d29eeb2a9.pdf (Caused by NewConnectionError("HTTPSConnection(host='web.archive.org', port=443): Failed to establish a new connection: [Errno 111] Connection refused"))