Appropedia's Public Domain Search is intended to be as complete as possible. However, there are some results which can't be included for technical reasons. These are listed here.
- The Google books search for books that are marked off as "Full View" books in Google, which in theory should mean they are public domain.[verification needed] However, sometimes these have a "Copyright material" watermarked. In any case, make sure of the copyright/public domain status before using the content.
- Internet Archive search - more reliable results. It is hoped to include results from this in Appropedia's Public Domain Search.