1. After writing the text, leave two blank lines and write the word "reference" in the middle; "Reference" is bold on the 4th, and there is no space between the two words. After writing the "reference", write a blank line (Song Ti Xiao No.4), and then write the specific content of the reference.

2. References are continuously coded with Arabic numerals according to the order in which they appear in the text. The serial number of the reference is written in the box at the top left and indicated by brackets.

3. References only list the documents directly read and mainly referenced by the author in the process of writing the paper, and the listed references should be arranged in the order of references of the paper. References and texts are numbered consecutively. There are no less than 6 references.

The format of reference is: [serial number]+author of the work+title or title of the article+type of reference+year or year of publication of the work, volume (issue)+":page number (or page number range)".

The marking format of graduation thesis cited by others is (graduation thesis type is dissertation [D]):[ serial number] principal, document title [D], publishing place: publishing unit, publishing year: starting and ending page numbers (optional).

For example: [1 1] Zhang Zhusheng. Invariant set of differential semi-dynamic system [D]. Beijing: Institute of Mathematics, Peking University Department of Mathematics, 1983: 1-7.