There are preconditions for SCl paper retrieval, which usually include doi number, issue number and volume number. In fact, only SCl papers with doi number were retrieved, and some SCl papers with doi number, issue number and volume number were retrieved after publication.

If SCI journals are not submitted to the database in advance, only do Scl papers can be retrieved at this time. If the examination is submitted in advance, the retrieved SCl paper has no volume number and issue number. Of course, what kind of SCl journals can be submitted for inspection after having the doi number needs to know the actual situation of the target SCI journals.