Paper reference refers to the list of documents listed by the author when he quotes, draws lessons from or refers to other people's research achievements, academic documents or related materials in the process of paper research and writing. Including the author, publication year, article title, journal name, volume number, issue number, page number and other information, so that readers can find the source of the literature used by the author, verify the authenticity and accuracy of the information, and further understand the relevant content if necessary.

The function of references in this paper is to show personal academic integrity, respect other people's research contributions, and at the same time facilitate readers to further learn and expand their knowledge in related fields. When writing a thesis, the author needs to quote and refer to the viewpoints, data and materials in the previously published literature to support and prove his argument. These cited documents are called cited documents in the paper.

The citation and labeling methods of references need to follow certain norms and standards, such as APA and MLA. When quoting literature, we should pay attention to the following points:

References should be related to the theme of the paper: when choosing references, we should ensure that the documents are related to the theme of the paper and support the views and arguments of the paper. At the same time, we should avoid quoting irrelevant or low-quality documents, so as not to affect the quality of the paper.

The order of quoting documents should be reasonable: when quoting documents in the text, they should be arranged in the order of quoting, usually including the order of the text and all tables, charts, appendices, quotations, etc. Therefore, when writing a paper, we should arrange the order and quantity of cited documents reasonably.

The labeling method of cited documents should be correct: when labeling documents in the text, you need to directly add the symbol words of the author and the year of the document, such as "[1]" or "(Smith, 20 10)" and so on. At the same time, we should also pay attention to whether the labeling strictly follows our own academic system.

Pay attention to intellectual property rights when quoting documents: when quoting documents, you should respect intellectual property rights and abide by relevant laws and regulations. For documents that need to be cited, it is necessary to obtain the author's permission or make reasonable quotations in accordance with regulations to avoid infringing on the intellectual property rights of others.