The Beatles release twelve original albums, twelve EPs (mainly consisting of material also available on their albums), one double EP, and twenty-two singles (mainly featuring original music not found on their albums) 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.