Question: Which is the posthumous work that was the notable work of Ludwig Wittgenstein?
Paraphrase: Which is the after death work that was the remarkable work of Ludwig Wittgenstein?
SPARQL (Wikidata):  select distinct ?obj where { wd:Q9391 wdt:P800 ?obj . ?obj wdt:P31 wd:Q17518461 } 
Answer: Philosophical Investigations