Megalovasilis, P., A. Godelitsas, G. Papastergios, and A. Filippidis. 2016. “ENVIRONMENTAL GEOCHEMISTRY OF PTOLEMAIS LIGNITES, INTERMEDIATE STERILES, AND COMBUSTION PRODUCTS”. Bulletin of the Geological Society of Greece 50 (4):2241-50. https://doi.org/10.12681/bgsg.14280.