I usually search on websites, such as Baiteng, soopat and National Bureau of Knowledge. Batten is easy to download, and soopat has more information. These can be found in domestic and world patents, which are generally enough. Of course, if English is ok, you can also go directly to the official websites such as the European Institute and the US Patent Office to search for foreign patents.
There are also some foreign countries such as official website and Europe. On the linked website of the National Bureau of Knowledge.