show me some hard-to-find search engines

1. DuckDuckGo - a privacy-focused search engine that doesn't track user data 2. Dogpile - a metasearch engine that retrieves results from multiple search engines 3. Yandex - a Russian search engine with a large index of websites and advanced search features 4. StartPage - a private search engine that uses Google's search results without tracking user data 5. Ecosia - a search engine that plants trees with its ad revenue and displays the trees planted so far on its homepage 6. Mojeek - an independent search engine that uses its own web crawler to provide unbiased search results 7. Gigablast - a search engine that indexes millions of websites and offers advanced search options 8. WolframAlpha - a computational knowledge engine that provides curated and structured data for user queries 9. BoardReader - a search engine specifically for internet forums and discussion boards 10. Gibiru - a search engine that claims to provide uncensored and anonymous search results.