Regular publications usually have two titles, one of which isIssn issueThe other one is..Cn issue(national standard no. Access to issn is relatively easy, while the cn issue is different. The registration of periodicals is regulated more strictly, and private persons or enterprises are not usually allowed to operate them, and the sponsors are generally state agencies or undertakings. Journals need to be inPress publicationThe administration registers and is reviewed annually and the registered journal receives a cn number. This issue is usually an important basis for job evaluation and university examination, and the lack of cn publications may be considered local or internal。
