Research. Other source information is provided by the U.S. Department of Energy, its contractors, other government agencies, professional societies. Engineering and software materials, references to journal literature, conferences, patents, books, monographs, and thesis, make up the files of this database. Approximately 50% of these references are from non-U.S. sources. See also List of academic databases and search engines References (Dept. of Commerce) Bibliographic databases and indexes Energy organizations Government databases in the United States Scientific databases United States Department of Commerce