Document retrieval is to quickly and accurately find out the information related to a specific scientific research topic from a large number of documents. Literature retrieval plays an irreplaceable role in college students' graduation thesis writing.

1. Literature retrieval is easy to inherit and learn from previous scientific research achievements and avoid repeated research.

2. Literature retrieval helps to save the time for college students to find literature and improve the quality of graduation thesis.

3. Literature retrieval stimulates students' creative thinking and research ability.