Virtuoso 37000 Error SP030: SPARQL compiler, line 0: Bad character '&' (0x26) in SPARQL expression at '&' SPARQL query: define sql:big-data-const 0 define sql:describe-mode "CBD" DESCRIBE <http://dati.lavoro.gov.it/lod/ff81ac85-2800-ff20-e054-020820d23886-structure>