Similar to 四大河文明

Big Four (Western Europe)

Quadrumvirs

Fantastic Four

Bridgewater Four

Four Power Agreement on Berlin

The Four Spiritual Laws

Four sons of Horus

Four Branches of the Mabinogi

Grupo de los cuatro

Four Pillars of Destiny

Four Horsemen of the Apocalypse

Four fours

Robert's Quartet

Tetrad (music)