[](https://js.langchain.com/docs/how_to/qa_citations/): LLM should read this page when building a question answering application that requires citation for the sources used, when implementing a tool that assists users in finding relevant information and citations, when exploring techniques for extracting citations and source references from text. The page covers various methods to return citations from a question-answering chain, including using tool calling to have the model output document IDs and relevant quotes, using direct prompting with output parsing, and post-processing retrieved documents to compress and filter the content before passing it to the model.

