Baidu Academic Search is an academic resource search platform that provides massive Chinese and English literature retrieval, covering all kinds of academic journals, degrees and conference papers. It aims to provide the best scientific research experience for scholars at home and abroad. Through Baidu Academic, you can find papers from academic websites such as HowNet, Wanfang and VIP. But Baidu Academic, as an information search engine, can't download papers directly. If it is downloaded, it will get the database.

2.BASEBASE is a multidisciplinary academic search engine developed by the Library of Bielefeld University in Germany, which provides integrated search services for heterogeneous academic resources around the world. It integrates the book catalogue of the University Library of Bielefeld, Germany, and the open source data of about 160 (more than 2 million documents).

3. China Link Service: an online retrieval platform for foreign periodicals developed and provided by China Book Import and Export Corporation. Cnp Linker (CNP Link Service) organized and developed by China Library Group Company provides readers with a convenient and quick comprehensive network platform for consulting various foreign periodicals. At present, * * * has collected more than 6.5 million contents and abstract data of more than 20,000 foreign periodicals (of which nearly 1 1,000 are open access periodicals) and kept it updated irregularly. The electronic full-text link of periodicals and the query function of domestic collections not only provide users with fast and flexible query and retrieval functions, but also provide convenience for users to quickly obtain the full-text content of foreign periodicals.

4. China HowNet is the concept of national knowledge infrastructure, which was put forward by the World Bank in 1998. CNKI project is an information construction project aimed at realizing the dissemination, enjoyment and value-added utilization of knowledge resources in the whole society. Initiated by Tsinghua University and Tsinghua Tongfang, it was established in June 1999. Provide CNKI source database, foreign language database, industrial database, agricultural database, medical database, economic database and educational database. Among them, the comprehensive databases include China periodical full-text database, China doctoral thesis database, China excellent master thesis full-text database, China important newspapers full-text database and China important conference literary theory full-text database. Each database provides three retrieval functions: primary retrieval, advanced retrieval and professional retrieval. Advanced retrieval function is the most commonly used.