Science20th centuryglobalhigh confidence

Cenograms were introduced in 1964 by J.A. Valverde.

Notes on verification

Corroborated by multiple independent peer-reviewed sources (ScienceDirect, Springer) citing the original 1964 Valverde publication in La Terre et la Vie. [tier=silver indep_score=0.77 clusters=2 claim_tier=notable]

Sources