Google a reliable site

I have recently found out that you can use Google to search within an specific website. This method works well in trying to narrow down your searches to sites which you consider a reliable source. For example, if you want to know if the term "action plan" is more commonly used than "plan of action" you can use Google using the following keywords:
"action plan" site: http://www.bbc.co.uk and then
"plan of action" site: http://www.bbc.co.uk
This will tell you which one is more often used by the BBC.