SELECT 	
	?item ?itemLabel
	(GROUP_CONCAT(DISTINCT ?instanceLabel; separator=", ") as ?i)
	(SAMPLE(?metricalPattern) as ?mp)
WHERE 
{
	?item wdt:P31/wdt:P279* wd:Q1651051 .
	?item wdt:P31 ?instance . 
	OPTIONAL { ?item wdt:P2552 ?metricalPattern }.
	SERVICE wikibase:label { bd:serviceParam wikibase:language "it,en" . ?instance rdfs:label ?instanceLabel . ?item rdfs:label ?itemLabel }
}
GROUP BY ?item ?itemLabel