What is the definition of first-hand literature? What are the types of primary literature? Information retrieval examination questions!

First-class literature: This is a literature produced by people directly according to their practical experience in production, scientific research and social activities, and it is also often called original literature (or first-class literature), and its recorded knowledge and information are novel, specific and detailed. Primary literature is the largest, most diverse, most widely used and most influential literature in the whole literature system, such as periodical papers, patent documents, scientific reports, conference proceedings, dissertations and so on.

The original literature has the following characteristics:

First, the original content is the author's own work experience, observation or actual research results. This kind of literature is advanced and novel, reflecting the latest research results in related fields;

Second, the contents of the literature are detailed and valuable for researchers to refer to, learn and use;

Thirdly, a large number of primary documents are scattered in various periodicals, media, conference records, books, serial publications and special documents, which is difficult to find.