(1) Full-text database of excellent doctoral and master's dissertations in China: At present, the full-text database of doctoral and master's dissertations in China, which has the most comprehensive resources and the highest quality in China, has been continuously updated, including outstanding doctoral and master's dissertations from 65438 to 0999 in 305 universities and research institutes with doctoral degree awarding qualifications. The retrieval methods include primary retrieval, advanced retrieval and professional retrieval, and the navigation system can be used for classified browsing.

(2)CALIS University Dissertation Database: It contains more than 70,000 doctoral and master's dissertations provided by 83 CALIS member libraries, covering natural science, social science, medicine and other fields. The retrieval methods include simple retrieval and advanced retrieval.

(3) China Dissertation Abstract Database: It contains the abstract information of doctoral, postdoctoral and master's dissertations in natural sciences since 1989. The retrieval methods include personalized retrieval, dictionary retrieval and advanced retrieval.

(4) Database of National Science and Technology Library: It contains master's, doctoral and postdoctoral papers published by universities, graduate schools and research institutes in China from 65438 to 0984. The retrieval methods include general retrieval, navigation retrieval and advanced retrieval.

(5) Websites of libraries of universities or scientific research institutions.