Is there a person anywhere in the world who knows every fact about every subject? No. It is impossible for one person to know everything. Fortunately, there are encyclopedias, almanacs, dictionaries, and many other kinds of materials that provide information on almost any subject imaginable. We call these special sources of information reference materials because people refer to them to learn the answers to their questions.

Let us say your teacher asks you to write a report on India. You can find all the information you need by selecting the right reference materials. Sometimes you will get enough information from a single book. Usually, though, you need to use several books or different kinds of reference materials.

You can find many important facts about India by using an almanac. It will have the population of India, the number of cars, the most important businesses, and more. An almanac has up-to-date facts because a new edition is published every year.

An almanac is a good first reference book for your report. But to get a deeper understanding of India, you should refer to an encyclopedia. An encyclopedia will have an article on India that will give the history of the country and list important cultural achievements. It will tell how the people of India live and include biographies of India's most influential men and women. You might want to find out more about the great Indian leader Mohandas Gandhi. If there is no biography of Gandhi in your encyclopedia, look in the Dictionary of National Biography. Here you will find a biography of Gandhi along with many other biographies.

To find out about current events in India you can read recent newspaper and magazine articles. The Readers' Guide to Periodical Literature lists articles from the most important magazines and newspapers published in the United States. Look up India and you will find references to many articles.

Reference materials can also be found by using computers. Several encyclopedias, including The New Book of Knowledge, are available either on CD-ROM or over the Internet. Many newspapers and other news organizations provide the latest news, as well as archives of previous events, on their Web sites. And the Internet itself has become a virtual reference "book" for information of all kinds, as businesses, organizations, and individuals create their own online "pages" to share their interests and knowledge with the world.

The Library of Congress, the largest library in the United States, has more than 70,000 reference books. Your local library does not have that many books, but all libraries have a good selection of reference materials. Your job is to find the right references for the information you need.

Do you want to know the location of Sri Lanka? Look in an atlas. Would you like to know what Abraham Lincoln said about slavery? Look for a book based on his life or one on the history of the United States. Do you need to find a well-known saying by a famous person? Try Bartlett's Familiar Quotations. Do you want information about violins? The Concise Oxford Dictionary of Music is a good source.

The more you know about reference materials, the easier it is to find information. Librarians are trained to know all about reference materials, and they can help you explore the reference section in your library.