ate ▁words ▁and ▁pla cen ames ▁in ▁other ▁Ind o - Europe an ▁languages , ▁complement ed ▁by ▁analysis ▁of ▁the ▁historical ▁evolution ▁of ▁such ▁pla cen ames . ▁However , ▁the ▁results ▁are ▁hypoth et ical ▁and ▁subject , ▁in ▁many ▁cases , ▁to ▁diver gent ▁et ym ological ▁interpret ations . ▁ ▁Re const ru ctions ▁derived ▁from ▁Roman ian ▁and ▁Alban ian ▁words ▁are ▁based ▁on ▁the ▁un pro ven ▁theory ▁( with ▁some ▁lingu ists ▁and ▁histor ians , ▁this ▁theory ▁has ▁become ▁an ▁assumption ▁) ▁that ▁Da cian ▁constit utes ▁the ▁main ▁lingu istic ▁substr atum ▁of ▁both ▁languages , ▁or ▁the ▁related ▁theory ▁that ▁Da cian ▁and ▁early ▁Alban ian ▁both ▁descend ▁from ▁an ▁immediate ▁common ▁ancest or . ▁ ▁Re const ruction ▁of ▁words ▁from ▁place ▁and ▁personal ▁names ▁ ▁Method ology ▁▁ ▁Both ▁Georg iev ▁and ▁Dur idan ov ▁use ▁the ▁compar ative ▁lingu istic ▁method ▁to ▁de ci pher ▁ancient ▁Th ra cian ▁and ▁Da cian ▁names , ▁respectively . ▁▁▁ ▁Georg iev ▁arg ues ▁that ▁one ▁can ▁reli ably ▁de ci pher ▁the ▁meaning ▁of ▁an ▁ancient ▁place - name ▁in ▁an ▁unknown ▁language ▁by ▁comparing ▁it ▁to ▁its ▁successor - names ▁and ▁to ▁cogn ate ▁place - names ▁and ▁words ▁in ▁other ▁IE ▁languages , ▁both ▁ancient ▁and ▁modern . ▁He ▁gives ▁several ▁examples ▁of ▁his ▁method ology , ▁of ▁which ▁one ▁is ▁summar ised ▁here : ▁ ▁The ▁city ▁and ▁river ▁( a ▁trib ut ary ▁of ▁the ▁Dan ube )