SCIENTIFIC STUDY OF 13C/12C CARBON AND 18O/16O OXYGEN STABLE ISOTOPES BIOLOGICAL FRACTIONATION IN GRAPES IN THE BLACK SEA, DON BASIN AND THE WESTERN CASPIAN REGIONS Article Kolesnov A., Zenina M., Tsimbalaev S., Davlyatshin D., Ganin M., Anikina N., Agafonova N., Egorov E., Guguchkina T., Prakh A., Antonenko M. 40th World Congress of Vine and Wine. OIV, Paris. 2017.