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If your ancestors referred to their origin as Russia in documents prior to WW1 then no doubt that it would be the smaller town from Russia,
because anyone that came from the larger city of Czernovitz, Bokovina - was a proud Austrian and would never call themselves Russians.
Even during the Romanian time between the wars.
Unless the documents are from after ww2 when Czernovitz, Bokovina was part of USSR and maybe your ancestors would refer to USSR as Russia. But I doubt it.
Researching (main surnames):
From Austria, Slovakia: LOFFLER / LEFLER, LEDERER, SCHNEIDER, NATHAN, SEELENFRIED, ZAPPERT.
From Bukowina, Galicia: MINSTER / MUNSTER, NAGEL, SCHERL, IWANIR.
From Poland / Belarus: ALTMAN, KAMINSKY, KAMINKIER, LUBETKIN, SZTARK, YOSELEWICZ, KOSLOWSKI, KRAMARZ, RAUCHFELD.