Apostolova, D., Stojanović, K., Kostova, I., Sachsenhofer, R., & Botoucharov, N. (2026). Organic Geochemistry and Biomarker Characterization of Eocene Coal from the Burgas Basin. Proceedings of the Bulgarian Academy of Sciences, 79(8), 1055–1065. https://doi.org/10.7546/CRABS.2026.08.06