query-62002a75b4be9be3873687634079afdb
Scientific papers without "main subject" SELECT ?item WHERE { ?item wdt:P31 wd:Q13442814 . OPTIONAL { ?item wdt:P921 ?dummy0 } FILTER(!bound(?dummy0)) }
Use at
- https://query.wikidata.org/sparql
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
#Scientific papers without "main subject"
SELECT ?item WHERE {
?item wdt:P31 wd:Q13442814 .
OPTIONAL { ?item wdt:P921 ?dummy0 }
FILTER(!bound(?dummy0))
}
Query found at
graph TD
classDef projected fill:lightgreen;
classDef literal fill:orange;
classDef iri fill:yellow;
v1("?dummy0")
v2("?item"):::projected
c2(["wd:Q13442814"]):::iri
f0[["not bound(?dummy0)"]]
f0 --> v1
v2 --"wdt:P31"--> c2
subgraph optional0["(optional)"]
style optional0 fill:#bbf,stroke-dasharray: 5 5;
v2 -."wdt:P921".-> v1
end