(1) books. Books have the characteristics of the largest variety, quantity and scope, and generally give people systematic, complete and continuous knowledge and information.

(2) periodicals. It has the characteristics of short publishing period, fast reporting speed, large quantity and new information content, and is a very important information source.

(3) newspapers. Its characteristics are timely reporting, wide audience, mass and popularity.

(4) Meeting documents. It is characterized by quickly and professionally reflecting new technologies and new achievements, and can comprehensively reflect the development level, trend and trend of a certain technical field or discipline.

(5) scientific and technological reports. It has the characteristics of divided volumes, uncertain publication date, profound content, rapid reporting, mostly secrecy and controlled distribution.

(6) standard literature. This is a binding, normative and legal document.

(7) Patent documents. It is detailed, novel, practical and timely.

(8) Dissertation. Its content is systematic, with certain depth and creativity.

(9) Technical files. It is a technical document with certain engineering objects.

(10) electronic literature. It has the advantages of large storage capacity, small volume and easy retrieval, storage and appreciation.

According to the publishing form, there are ten kinds: scientific books, scientific journals, patent documents, conference documents, scientific reports, government publications, dissertations, standard documents, product materials and other documents.