Megalovasilis, P., A. Godelitsas, G. Papastergios, and A. Filippidis. “ENVIRONMENTAL GEOCHEMISTRY OF PTOLEMAIS LIGNITES, INTERMEDIATE STERILES, AND COMBUSTION PRODUCTS”. Bulletin of the Geological Society of Greece, vol. 50, no. 4, July 2016, pp. 2241-50, doi:10.12681/bgsg.14280.