First, turn on the computer, enter the website of the campus network in the browser, and log in to the campus network. Then in the browser, search official website, click Enter, find the library, and click Enter. There must be a school campus network. If HowNet is bought by the school, it is unnecessary for that person to log in. Just click on HowNet.

Second, you will see electronic journals, other resources and use resources in the webpage. Look up the full-text database of China journals (CNKI), click enter, see "main site", and click enter the homepage of HowNet.

Third, you will see cross-database selection and advanced retrieval in the upper right corner of the homepage, and select advanced retrieval. If the school doesn't buy HowNet, the literature can't be downloaded for free. Enter what you are looking for. If you want to find: the extraction process of proanthocyanidins, search with keywords. If the literature to be retrieved is generally in the last five years, the time can be limited to the publication time.