View source for Wikidata SPARQL GND

https://w.wiki/6oWf
 SELECT ?id
 {
  ?item wdt:P31 wd:Q5.
  ?item wdt:P227 ?id. 
  ?item wikibase:sitelinks ?sl.
  FILTER (?sl >= 1).
 }

https://w.wiki/6oWr
 SELECT ?id
 {
  ?item wdt:P31 wd:Q5.
  ?item wdt:P227 ?id.
  FILTER EXISTS {
   ?article schema:about ?item .
   ?article schema:isPartOf <https://de.wikipedia.org/>
  }
 }

https://w.wiki/Rkt
 SELECT (COUNT(DISTINCT(?item)) AS ?count_item) (COUNT(DISTINCT(?id)) AS ?count_did) (COUNT(?id) AS ?count_id) 
 {
  ?item wdt:P31 wd:Q5.
  ?item wdt:P227 ?id.  
 }