If you are asking an LLM to cite it's sources you are wasting your time and degrading the quality of the response. LLMs have no inherent mechanism for "knowledge source tracking", because that isn't at all how they work. We're trying to get there with agentic stacks, but it's still too new.

For sparse knowledge tasks, where you know that the model can't possibly have much training because even humans themselves don't have much knowledge there, use it as a brainstorming partner, not as a source. Or put relevant papers in it's context to help you eval those papers in relation to your work. But it's just going to hurt itself in confusion trying to tie fuzzy ideas to sparse sources embedded in pages upon pages of mildly related google search results.