Resource Overview Alternate Title(s): DOE Information Bridge, Energy Citations Database Link to Resource Connect to Resource The Energy Citations Database (ECD) provides free access to over 2.6 million science research citations with continued growth through regular updates. There are over 221,000 electronic documents, primarily from 1943 forward, available via the database. Citations and documents are made publicly available by the U.S. Department of Energy (DOE). ECD includes scientific and technical research results in disciplines of interest to DOE such as chemistry, physics, materials, environmental science, geology, engineering, mathematics, climatology, oceanography, and computer science. It includes bibliographic citations to report literature, conference papers, journal articles, books, dissertations, and patents.