Bessarabia South Russia Ukraine
A big part of finding locations in this part of the world is the naming.
As a starter, find out what “exonyms” are!
Most of the German-Russian mother colonies in what is now Ukraine were not at the site of existing villages. They were named at the time of settlement. During and after the Russian revolution and then the breakup of the Soviet Union, the villiages and provinces changed names.
In my genealogy reports, I will try to list the locations by their current names, with notes as to their names at the time of settlement. This is contrary to what many genealogists are doing.
Some place name resources for this area: