Geochemical characteristics of bottom sediments of Lake OnegaE.I. Valieva, E.N. Poludetkina, O.N. Vidishcheva, A.K. Mirinets and A.E. RybalkoE3S Web Conf., 266 (2021) 07010DOI: https://doi.org/10.1051/e3sconf/202126607010