00709naa#a2200193#i#450# EN\\bibl\114320 20260314000428.6 2712-7761 20260130b2026####ek#y0engy0150####ca RU Organic matter geochemistry of Quaternary sediments of the Seyda River valley (northeast of the Pechora Lowland) Journal article Syktyvkar FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences" 2026 10 с. Journal article local Биогеохимия. 550.47 Burdelnaya N. S. Marchenko-Vagapova T. I. Bushnev Dmitry Alekseevich ras.editorum.ru