To search for medical information pdf documents in Google, you should construct the search formula like this:
1. Open your computer browser and enter the homepage of PubMed.
2. When using PubMed to search medical literature, you need to enter keywords in the search box to proceed to the next step.
3. At this time, 20 search results will be displayed on each page, and you can accurately filter based on factors such as time, abstract or type.
4. If there is no problem in this way, you can directly click on the relevant link to enter and use PubMed to search for medical literature.
Retrieval expression is one of the specific embodiments of retrieval strategy, which is called retrieval formula.
Search formulas usually consist of search terms and various logical operators. Specifically, it is a type of search command that can be recognized and executed by a computer by connecting logical relationships and positional relationships between search terms with various operators specified by the search system. The advantages and disadvantages of the search structure are related to the success or failure of the search strategy.
The expression structure (*) in common searches represents any string. %: Represents one or more arbitrary strings. For example, "Chinese %" and "Daily News %" find infinite-length words starting with "Chinese" and ending with "Daily News" respectively.