1, Google Academic: Google Academic is an academic search engine launched by Google, which can search academic documents, academic papers, academic journals and academic books. Google Academic has collected academic resources from all over the world, and the search results include detailed information such as literature abstracts, author information, citations, related papers and so on.

2. Baidu Academic: Baidu Academic is an academic search engine launched by Baidu, covering academic documents, academic journals, academic papers, dissertations and conference papers. Baidu Academic provides academic search, document search, paper download and other functions, as well as full-text retrieval, citation analysis, document delivery and other services.