The Electoral Knowledge Network provides comprehensive information and specialised advice on any aspect of electoral processes (2018).

Wikipedia explains the various electoral systems (2018)  

Vereinigung zur Reform des britischen Wahlsystems (2015)

The world map shows the different voting systems (2018).

Germans elect their members of parliament with two votes (2021).

Alan History Nerd explains how the different electoral systems used in the UK work (UK 2020).

Site of the the body that elects the President and Vice President of the United States every four years (The National Archives and Records Administration 2020)

The lesson seen in the video culminates a 12-week unit to engage students in the civic life of their community. It was videotaped just prior to the 2002 mayoral election in Newark, New Jersey (USA: Annenberg 2018).

The independent body which oversees elections and regulates political finance in the UK (2018)

This information source provides timely and accurate election statistics, electoral laws, research reports, and other useful information regarding the United States electoral system (USA: University of Florida 2018).