Čeru, Teja, Matej Dolenec, and Miloš Markič. 2015. “Mineral Composition of Sediments Underlying the Velenje Lignite Seam in the P-9k/92 Borehole (Slovenia)”. Geologija 58 (1):7-34. https://doi.org/10.5474/geologija.2015.001.