As a superb example of information about Mongolia being available but not practically accessible, one of our interns this summer has come across the URL for an electronic version of the Mongolian Statistical Yearbook at the National Statistics Office. You'll note that the URL has no domain name but rather an IP address. It has not been indexed by Google, so although the document is on the Web, you have to know where it is to find and use it. Makes me wonder how many other useful documents are just floating out there at http://randomIPaddress/?
Check out the yearbook at http://188.8.131.52/yearbook/2007/yearbook2007.pdf.