CIA - The World Factbook
The first classified Factbook was published in August 1962, and in June 1971 appeaered the first unclassified version of it. In 1973 the NIS program was terminated in except for the Factbook, map and gazetter compnents of it. The Factbook, which was published in 1975 is considered to be the first available for the public with sales through the Government Printint Office of the United States. As for the availability of the Factbook on the Internet, this happened in June 1997. In 2003 the Central Intelligence Agency celebrated its 56th anniversary, and its 60th year of continuous basic intelligence support of the United States Government by the World Factbook and the two programs, which were its predecessors. 

Columbia Encyclopedia
There are about 51,000 entires (marshalling six and one – half million words on a vary wide range of topics) and more than 80,000 hypertext cross – references in the current Sixth Edition of the Columbia Encyclopedia, which is considered to be the most complete and up – to – date one ever produced.

Encyclopedia.com
Internet users can find more than 57,000 frequently updated articles from the Sixth Edition of the Columbia Encyclopedia on the Encyclopedia.com Website. It should also be noted that each article has links to the newspaper and / or magazine arricles, and pictures and maps, which are provided by eLibrary.

Wikipedia
Wikipedia is the project of collaboration of contributors from all over the world. It is a free content wiki encyclopedia, in which there are 251003 articles, written in English. Every day hundreds of thousands of Internet visitors from around the world make dozens of thousands of edits and create thousands of new articles.

Google Scholar
With the help of Google Scholar it is possible to search specifically for some kind of scholarly literature, including abstracts, books, peer – reviewed papers, preprints, technical reports and thesis from all possible areas of research. People can also apply to this site in case if someone wants to find articles from a variety of academic publishers, professional societies, preprint repostitories and universities. In addition, scholarly articles are also available across the web. 

MSN Encarta - Encyclopedia Article Center
Apply to this Website and search more than 4,500 articles on the keyword. Everything, beginning from aardvark to Zambia is available at this site.

HighBeam Research
This is an extensive archive, which contains more than 32 million documents form 2,800 sources. There is a vast collection of articles from leading publications, which are updated on a daily basis, and which go back as far as 20 years. it is possible to save your searches, save articles and set up alerts to save time and increase your efficiently. It is also necessary to point out that HighBeam Research provides basic (free), as well as full membership options for its users.

Questia
Questa is considered to be the first online library, which provides 24 hours and 7 days a week access to the online collection of books and journal articles in the humanities and social sciences, in the world. In addition, different magazine and newspaper articles are also available at this site. It is possible to search each and every word of all of the books and journal articles from the collection. It is also possible to read every title cover to cover. Therefore, it is necessary to point out that this Website requires its users to subscribe on a monthly, quarterly or yearly basis.