title_body: Public domain search tools/websites Is there a united resource or program to search public domain works?
  By united I mean it searches in more than 1 website for my search term.
upvoted_answer: The internet archive https://archive.org/ lists both works they host as well as works in other libraries.  While most (all?) of the ebook are available without cost the majority are public domain works, there are also many Create Commons &amp; fair-use works. There is not a good way to search for only PD works, but due to the type of results returned that should not be an issue for most users.  The works that are not PD, are mostly appropriate for attribution sharing, which mostly allowed.
  
  (There are not any absolutes here) 
  
  Selecting texts will return everything that is mostly written words. From single page documents to books. This is approximately equal to 'ebooks'.