Complex sentence: Some historians believe that the Volhynians and the Buzhans are descendants of the Dulebes, or a few historians claimed the name came from Celtic tribes known as "Bolihii" before the arrival of Slavic tribes in the 6th century.
Split into simpler sentences: Some historians believe that the Volhynians and the Buzhans are descendants of the Dulebes. A few historians claim the name comes from Celtic tribes known as "Bolihii" before the arrival of Slavic tribes in the 6th century.