This is a really easy problem to solve. You simply fetch those documents and add them to the context, or use another LLM to summarize them if they are too large. Then, have another fact checking LLM be the judge and review the citations.
You got the Groucho Marx gag wrong. He said “a child of five could understand this” and requested a child of five in order to help him understand it (implying he was stupid).
