Due to the development of the times, the previous reasons may be out of date today, so if the content of the references cited in the paper is highly applicable, it is generally required to relax to 15 years within 10 years, and outdated documents are not cited. The actual situation is completed according to the requirements of the institution.

Literally, a reference is a document cited in the writing process, such as an article or a book. However, according to the definition of GB/T 77 14-20 15, the reference after the text refers to the relevant literature information resources cited for writing or editing papers and works.