Dissertations are highly academic research papers written by undergraduates and postgraduates in institutions of higher learning and scientific research in order to obtain degree qualifications (doctor, master and bachelor). It is completed on the basis of consulting a large number of documents and conducting scientific research in study and research.

The characteristics of the paper are: theoretical, systematic, concrete, detailed and original, and it is an important source of literature information.

Dissertations are not only collected in this unit, but also in units designated by the state. The designated units for the collection of master's and doctoral dissertations in China are China Institute of Science and Technology Information and National Library. China's dissertations database can be used to retrieve domestic dissertations, and Dialog international online system or comprehensive index of international dissertations, American doctoral dissertations and dissertations edited and published by University Micro International can be used to retrieve foreign dissertations.