I also know that many students are manuscripts and newspaper articles, and the results can not be detected in school papers. This situation does exist. The knowledge of many books is not included in the large database of the paper duplicate checking system, but the newly published ones are basically included. Because the current technology can be collected and preserved.
The production of chronological books is unlikely to be included for a long time, but there is no guarantee that it will not be included, and the number of citations will increase, and the database of online papers will also be included. With the continuous upgrading and updating of the database of the paper duplicate checking system, more and more copies will be collected, the duplicate checking database will become richer and richer, and the probability of being found out will become greater and greater.
In the paper duplication checking system, instead of worrying about whether it will be duplicated, it is better to use other methods to reduce the repetition rate of copied content, try to make it have the same meaning and express different sentences.