*[http://www.scielo.org.ar/scielo.php?pid=S0365-03752004000200005&script=sci_arttext L.E. Cascarini de Torre, A.E. Fertitta, E.S. Flores, J.L. Llanos, E.J. Bottani: ''Characterization Of Shungite By Physical Adsorption Of Gases.''] The Journal of the Argentine Chemical Society, Bd. 92 Nr. 4-6, Buenos Aires 2004 (englisch)