According to GB3469-83 "File Types and File Carrier Codes", reference file types and file types are identified by a single letter:
Monograph-m; Newspaper-n; Journal-j; Patent literature-p; Compile-g; Ancient books-o; Technical standard-s; Dissertation-d; Science and technology report: reference tool-K; Search tool-w; Document-b; Audio tape-a; Chart-q; Record-l; Product sample-x; Video tape-v; Meeting minutes-c; Chinese translation-t; Music score-I; film-y； Manuscript-h; Microfilm-u; slide-z； Microfilm-f; Other-e.
Literature can be divided into first-class literature, second-class literature and third-class literature according to its content, nature and processing mode.
1, a literature:
A document is a document directly produced by people on the basis of their own practical experience in production, scientific research and social activities. It is also often called an original document (or a kind of document), and its recorded knowledge and information are novel, concrete and detailed.
2, the secondary literature:
Secondary literature is a kind of literature produced by processing primary literature, such as bibliography, title record, introduction, abstract and other retrieval tools.
3. Three documents:
It is a document compiled by comprehensive analysis on the basis of primary and secondary documents. People often refer to this kind of literature as the results of "information research", such as review, special review, annual summary of disciplines, progress report, data manual and so on.
Reference to the above content: Baidu Encyclopedia-References
Refer to the above content: Baidu Encyclopedia-A Literature