Guliev, Igbal, Alisa Khubaeva, Ester Markelova, Andrey Matveev, and Valery Kleshchev. 2023. “Bulgarian Green Energy: A Contradictive Choice of Future and Finance”. Journal of Mines, Metals and Fuels 70 (11):602-9. https://doi.org/10.18311/jmmf/2022/31378.