query: SELECT ?item ?inv (year(?collectiondate) as ?collectionyear) ?rkdurl WHERE {
    wd:P350 wdt:P1630 ?formatterurl .
    ?item p:P195 ?collectionstatement .
    ?collectionstatement ps:P195 wd:Q190804 .
    ?item wdt:P217 ?inv .
    FILTER regex(?inv, "^SK-A-3\\d{3,3}(-\\w)?$") 
    OPTIONAL { ?collectionstatement pq:P580 ?collectiondate }  .
    OPTIONAL { ?item wdt:P350 ?rkdid }.
    BIND(REPLACE(?rkdid, '^(\\d+)$', CONCAT("[", ?formatterurl, " $1]")) AS ?rkdurl)  .  
    } ORDER BY xsd:integer(REPLACE(?inv, "^SK-A-(\\d+)(-\\w)?$", "$1")) ?inv
  LIMIT 2000