in this index

Do not expect a complete index of everything that has ever been published on the Internet. This was never our intention. Every index has a scope.
The scope of this index comprises the publications of the selected publishers., which are most regarded for their accuracy and their fact-checking.

Tech detail: This search-index is initially created by crawling the selected websites.
Metadata, for instance the publishing date, would be more precise if the contributions were active, by sharing the local indexes to this intersite one.
Daily rss-feeds are used to update the index.