As long as foreign documents are written in non-Chinese, whether written by China people or foreigners, as long as they are not written in Chinese, they can be regarded as foreign documents. When writing a thesis, both undergraduate and graduate students should refer to the literature. Besides China's literature, they should also refer to foreign literature, most of which are written in English.

Literature is divided into Chinese and foreign languages by language, regardless of the nationality of the author. What is published in domestic journals is domestic, and what is published in foreign journals is foreign. In addition, foreign literature reflects the advanced level of science and technology in all countries of the world.

Search documents in a targeted way

At present, the databases of university libraries are relatively complete, and even if they are incomplete, documents can be obtained through various means on the Internet.

1, the core journal literature in this field. There are different core journals in different research directions, so we can't just say if here. Of course, first of all, you need to know what are the core journals in your research field, which depends on the mutual help of seniors, bosses or online comrades.

2. Literature in the field of cattle or major research groups. There are several leading figures in every field, and the direction they are engaged in often represents the mainstream of current development. Therefore, reading the literature in these groups can grasp the current research hotspots.

Search the literature in this field in ISI, and use the refine function to find out the authors or research groups with a large number of papers; Another way is to know what major international conferences there are in this field. Generally, you can see the name of the invited speaker on the website of the conference organizer, and the reporter who invited the report can do it.

3. Articles with high citation rate. Generally speaking, articles with high citation rate (if not by self-citation) are classic articles. Read more articles like this to understand the author's grasp of the article structure and the handling of chart analysis. I believe we can learn a lot from it.