Question: Tell me the historical ethnical group which has Eastern Iranian languages as native language and starts with the letter s?
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q4204501 . ?sbj wdt:P103 wd:Q391015 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 's')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25