Oguy, O. et al. 2021. Middle Ages Christian Colour Precious Stones Symbols in the Context of a new Conception of Symbol as a Synergetic Linguo-Cultural Hyper Sign. Mediaforum : Analytics, Forecasts, Information Management. 9, (Dec. 2021), 275–286. DOI:https://doi.org/10.31861/mediaforum.2021.9.275-286.