Find all Wikidata items that use a particular P18 picture

Question

I want to find all Wikidata items that have "Gthumb.svg" as a P18 property.

Leaving aside the fact that "Gthumb.svg" may not exist on Commons and that normal P18 values have a "commons:" prefix, it should return at least this item whose P18 is "Gthumb.svg":

https://www.wikidata.org/wiki/Q11499608

So, I wrote this query:

SELECT ?item
WHERE 
{
  ?item wdt:P18 "Gthumb.svg".
}

Problem: It returns zero results. What am I doing wrong?

Answer 1

As pointed out by Stanislav Kralin, here is the correct query:

SELECT ?item
WHERE 
{
  ?item wdt:P18 <http://commons.wikimedia.org/wiki/Special:FilePath/Gthumb.svg>.
}