Population Reference Bureau
Use 
This website provides a powerful keyword search engine and a detailed datafinder for locating records. Great attention to general usability, including printer-friendly, page email features, as well as customizing tools are offered.
Searchability 
A keyword search is available, along with a a pop-down menu for browsing through topics or categories. Moreover, a datafinder is provided to search on the main database covering variables for more than 220 countries worldwide
Downloading
Plenty of documents (data-sheets, research papers, graphics, etc.) are available as free downloads in pdf format. Also provided is a free email newsletter.
Navigational Aids
Very well-designed and thanks to its great attention to general usability, this website is very easy to navigate despite the lack of specific aids or an help section
User Friendliness
Users can access each page in a printer-friendly format and also email it. They can also create a personal profile and buy PRB material directly online, with a shopping cart and credit card options