1, using MeSH to expand keywords: MeSH is a sharp weapon to summarize synonyms in Pubmed. It can avoid synonyms and abbreviations being included in the search scope, avoid missing the desired documents in multiple searches, and greatly improve the search efficiency.

2. Accurately lock keywords: if the corresponding phrase is found, it will be searched as a search word; if the corresponding phrase is not found, it will be divided into single words to search separately. Therefore, infectious bowel disease tumor necrosis factor is equivalent to infectious bowel disease tumor necrosis factor.

3. Classification view: The overall results retrieved by Pubmed are unclassified, so researchers need to read the classification themselves or use filters for screening. Therefore, it takes a lot of time and energy to view targeted articles. The clinical query in PubmedTools on PubMed homepage can make researchers find relevant literature conveniently and quickly.

4. English periodical query: When the magazine name or ISSN number (international standard periodical number) is known, select "NLM Catalogue" in the classification option of the Pubmed search box, enter the magazine name (restricted by quotation marks) or ISSN number in the search content box, and click Search to search.

Search:

Retrieval refers to the process of finding the information or materials you need from information collections such as literature and network information. Traditional literature materials need to extract the title, author, publication year and subject words as indexes, but in the network age, computers can index the full text, that is, every word in the text can be a search point.

There are two main ways to search online: browsing the directory and using the search engine. Search engine is the most commonly used network retrieval tool. The tool often used in traditional literature retrieval is the index card, which records the information of literature on the index card. The index card generally records the title, author, subject words, abstract and other information of the literature.

When looking for a document, you should first check the index and find the location of its collection, and then ask for information. In the network age, we are looking for it all the time. There are two main ways to search on the Internet: directory browsing and using search engines. The way to browse the directory is the way used by Yahoo search engine. Users can click on the directory according to their own needs.