Background sources such as, but not limited to, dictionaries and encyclopedias provide context for your topic or even help you choose one. Researchers use them when they need:
Encyclopedia and dictionary entries for most subject areas. Dates covered: latest edition of each title.
Ebooks on most subject areas. Read online or set up an account to download or print up to 30% of pages. Please close or "release" a book when you are finished. Coverage: varies.
Encyclopedia, dictionary and biographical entries from hundreds of sources for most subject areas. It includes images, diagrams, maps and photos, and audio pronunciation files and sound clips. Coverage 2000 – present.
Encyclopedia entries from McGraw-Hill's Encyclopedia of Science & Technology. Also includes biographies of well-known scientific figures, downloadable images, videos and animations illustrating key topics. Coverage: Latest edition.