The 2005 CIA World Factbook

by United States. Central Intelligence Agency

Andorra
18 years of age; universal

Angola
18 years of age; universal

Anguilla
18 years of age; universal

Antigua and Barbuda
18 years of age; universal

Argentina
18 years of age; universal and compulsory

Armenia
18 years of age; universal

Aruba
18 years of age; universal

Australia
18 years of age; universal and compulsory

Austria
18 years of age; universal; compulsory for presidential
elections

Azerbaijan
18 years of age; universal