Thanks much for the discussion (from original question asker).
What i learned is that apparently the "regular" search (if you just type into the search box) does not search the URL field. Too bad, i would have expected it to do so. Also apparently the "*" at the end is mandatory. Even though "theguardian.com" would match, within the string, anything from that URL base, it does not return results unless the "*" is at the end. Very cumbersome...but at least i know what to do to find what i want!