The same document appears multiple times. How to be a reference? The number of the same document is different. In the reference, something similar to the following should appear.

When you quoted this document for the first time in your article, what was the ranking of this document in the list of references, such as the fourth place, so when you continue to quote this document in later articles, you only need to mark 4 in the upper corner. That is to say, in the case of repeated citation, the labels of the documents cited in this paper do not have to be arranged in the order from small to large.

The regulations of some schools are very irregular. He asked that the documents in the article should be numbered in sequence, and then all the following references, such as the seventh, twenty-fifth and thirtieth articles, are the same reference, which is actually incorrect. The same document can only appear once in the reference list.

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 document p; Compilation g; Ancient books o; Technical standards.

Dissertation d; Scientific and technological report; Reference tool k; Search tool w; File b; Tape a.

Chart q; Record l; Product sample x; Video tape v; Meeting minutes; Chinese translation T.

Music score I; Movie y; Manuscript h; Microfilm u; Slide z; Miniature flat film f; Other e.

Reference to the above content: Baidu Encyclopedia-References