Data Sources

Where every number on ATLAS comes from: official election authorities for results, and the polling companies behind every poll.

Austria

Results 1945-2002: Federal Ministry of the Interior, history tables
Results 2006-2024: Federal Ministry of the Interior, bundeswahlen.gv.at
Map: Natural Earth (public domain)

Germany

Results 1949-2025: The Federal Returning Officer (Die Bundeswahlleiterin)
Constituency maps: Die Bundeswahlleiterin (1998 on) and ZEIT ONLINE (1949-1994)

Latvia

Results 2026: Central Election Commission (CVK), by polling station
Map: Eurostat GISCO, LAU 2023 (© EuroGeographics)

Portugal

Results 1975-2025: Ministry of Internal Administration (SGMAI)
Maps: Direção-Geral do Território, official administrative map (CAOP)

Serbia

Results 2026 (preliminary): Republic Electoral Commission (RIK), by polling station
Map: Eurostat GISCO, LAU 2023 (© EuroGeographics)

Spain

Results 1977-1986, seats: Ministry of the Interior, via electionresources.org
Results 1989-2023: Ministry of the Interior, via the MiCongreso project
Map: Natural Earth (public domain)

Sweden

Results 2026: Election Authority (Valmyndigheten), by voting district
Maps: Valmyndigheten, voting district borders 2026

Opinion polls

Every country's polls come from Wikipedia's lists of opinion polls for its next election, which cite each polling company's own publication.