Patent retrieval and service system of China Bureau:/sipopublicsearch/portal/index.shtml;
EPO- Search European Monopoly Office's patents are extremely comprehensive, and it also provides translations in various languages.
Patent retrieval; ;
WIPO WIPO-search international and national patent collections;
Patent of Japan Patent Office &; Utility model bulletin database;
Kipris (Korea Intellectual Property Information Service), a free patent information search service;
3. Because of the openness of patent information, many of the above retrieval systems contain patent information from more than one country. For example, the system of the European agency contains a lot of patent information of the United States and Japan. In addition, there are many commercial or non-commercial non-governmental websites that also provide comprehensive patent information retrieval.