The Beatles released twelve original albums, twelve EPs (featuring mostly otherwise available material), one double EP, and twenty-two singles (featuring mostly otherwise unavailable material) in eight years (1962-1970) in their native United Kingdom. Their international discography is complicated, however, due to sometimes different versions of their albums released in other countries, particularly in their early years on Capitol Records in the United States. In addition, most of their releases are available in both mono and stereo mixes.