After fifteen months of work, the research culminated in two reports, "Use of Uranium for a Bomb" and "Use of Uranium as a Source of Power", known collectively as the MAUD Report. These reports discussed the feasibility and necessity of an atomic bomb for the war effort and its potential as to substitute for coal or oil as a source of energy. In response, the British created a nuclear weapons project officially named Tube Alloys. The MAUD Report was made available to the United States, where it energised the American effort, which eventually became the Manhattan Project. The report was handed over to the Soviet Union by its atomic spies, and helped start the Soviet atomic bomb project.