P. Koukakis, P. Tsakiridis, A. Ntziouni, K. Kordatos, and M. Perraki, “ATTAPULGITE CLAY OF THE VENTZIA BASIN, WESTERN MACEDONIA, GREECE, AS TEMPLATE IN SYNTHESIZING AMORPHOUS CARBON NANOTUBES”, geosociety, vol. 50, no. 4, pp. 1895–1902, Jul. 2016.