PatSnap https://lib.sustech.edu.cn/2021/0714/c530a4919/page.htm
China National Intellectual Property Administration: http://english.cnipa.gov.cn/
Patent star search system: http://search.patentstar.cn/My/SmartQuery.aspx
European Patent Register and national registers: https://worldwide.espacenet.com
The United States Patent and Trademark Office (USPTO) :https://www.uspto.gov/
WTO Intellectual Property Organization: https://www.wipo.int/portal/en/index.html
Please refer to the website of China Patent Information (for overseas patents): http://www.patent.com.cn/
For full-text documents or more information of patents registered in China and in other countries, please apply through Interlibrary Loan / Document Delivery.
