E.g. "Japan's App Store antitrust case"
https://www.perplexity.ai/search/Japans-App-Store-GJNTsIOVSy...
LLM training sees these documents without context; it doesn’t know where they came from, and any such attribution would become part of the thing it’s trying to mimic.
It’s still largely an unsolved problem.
ChatGPT Browse and Bing and Google Bard implement the same pattern.
RAG does allow for some citation, but it doesn't help with the larger problem of not being able to cite for answers provided by the unassisted language model.