Free and careful use, first of all, the free system can not find the real results, the paper may be leaked. At present, there are official channels of HowNet. You can check it at school. If the number of times is not enough, you can find the duplicate checking website online. But we must pay attention to identify the true and false duplicate checking websites, don't blindly believe in free duplicate checking websites, and don't trust low-priced duplicate checking websites.
Literature review of papers that students are not usually required to take in the school. The literature review of the paper has no practical value. However, some schools require students to upload papers and literature reviews to the paper duplicate checking system for testing, but generally speaking, this situation will not include the duplicate checking results in the final paper duplicate checking rate. However, it is only necessary to use the form of literature review when checking duplicate papers. When duplicate checking, the paper duplicate checking system generally marks this part with green font. Besides, the school is more convenient. When copying a paper, you only need to upload the text of the paper and don't copy other contents, which not only saves the cost of duplicate checking, but also is convenient.