Find any research articles for the user prompt optimization based on RAG and LLM in the prompt engineering field, if there exists. **Do not invent or guess; **Look at the most recent papers from 2022-2026. **Search the internet for more recent papers. **Eliminate the results that focus only on prompt engineering techniques in LLMs, not prompt generation or augmentationt prompt generation or augmentaion or optimization. **Return the full citation A research paper on auto-prompting like GEPA: Reflective Prompt Evolution Can Outperform Reinforcement Learning (https://arxiv.org/abs/2507.19457)