Cenograms were introduced in 1964 by J.A. Valverde.
Notes on verification
Confirmed by multiple independent peer-reviewed academic sources (ScienceDirect, Springer) citing Valverde's 1964 publication in La Terre et la Vie as the origin of the cenogram method.
Sources
- Cenogram (en.wikipedia.org)
- https://www.sciencedirect.com/science/article/abs/pii/S0031018208006299 (sciencedirect.com)
- https://sciencedirect.com/science/article/abs/pii/S0016699507000794?via=ihub%3D (sciencedirect.com)
- https://www.sciencedirect.com/science/article/abs/pii/S0031018210002312 (sciencedirect.com)
- https://link.springer.com/article/10.1007/BF02436623 (link.springer.com)