List of Google Dorks to search for companies that have a responsible disclosure program or bug bounty program which are not affiliated with known bug bounty platforms such as HackerOne or Bugcrowd.
Some of the dorks are sourced from Nightwatch Cybersecurity https://wwws.nightwatchcybersecurity.com/2019/05/04/finding-unlisted-public-bounty-programs-with-google-dorks/