The first data on the concentration and emission of methane and carbon dioxide in the underground sources of the Peshernaya beam of Lake BaskunchakDmitry N. Garkusha, Yury A. Fedorov, Evgeny A. Kovalev, Yuri A. Andreev and Natalia S. TambievaBIO Web Conf., 83 (2024) 04007DOI: https://doi.org/10.1051/bioconf/20248304007