Apostolova, Denitsa, Ksenija Stojanović, Irena Kostova, Reinhard Sachsenhofer, and Nikola Botoucharov. 2026. “Organic Geochemistry and Biomarker Characterization of Eocene Coal from the Burgas Basin”. Proceedings of the Bulgarian Academy of Sciences 79 (8). Sofia, Bulgaria:1055–1065. https://doi.org/10.7546/CRABS.2026.08.06.