1, a global patent search engine, is a free search service website provided by the European Patent Office, which contains information on rights documents of most countries and regions in the world, including patents, trademarks and industrial designs.
2. China HowNet, a knowledge discovery network platform, provides domestic and foreign readers with unified retrieval, unified navigation, online reading and downloading services for China academic literature, foreign literature, dissertations, newspapers, conferences, yearbooks, reference books and other resources.
3. China Patent Network is the official website of China National Intellectual Property Administration, China, and it is a platform providing patent information inquiry, analysis and research services.