TY JOUR TI Composition of hydrocarbons-biomarkers of bitumoids of different-aged deposits of the Timan-Pechora and Volga-Ural oil and gas provinces KW bitumoid KW chemofossils KW biomarkers KW hopanes KW steranes KW hydrocarbons JO Vestnik of geosciences AU Galiakhmetova, L.K. AU Markelov, R.A. AU Muhamatdinova, R.E. AU Mukhamatdinov, I.I. AU Vahin, A.V. PY 2025 IS 0 PB FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences"