Thank you for any information or direction to an authoritative source.

Most authoritative sources before 2008 considered the agent's fiction as fact.

An explanation from some authoritative source could go a long way," I tell her.

The work remains an authoritative source, but not without criticism.

No authoritative source for the location or date of his birth has yet been found.

This site should not be cited as an official or authoritative source.

There are more authoritative sources if you do a bit of googling.

It is considered to be one of the most authoritative sources on Islamic history.

The authority must become the authoritative source of scientific advice and information on food safety issues.

The books became authoritative sources for others writing about film.