Does anyone know if there is a “wikipedia-only” or way to constrain the knowledge of a LLM (trained on a more limited set of sources or constrained by limited s

Does anyone know if there is a “wikipedia-only” or way to constrain the knowledge of a LLM (trained on a more limited set of sources or constrained by limited sources of facts)? I think a LLM interface to Wikipedia could be useful, at least I imagine it would.