Complex sentence: The incident took place between September 26,1959 and the end of December, 1959, and the victims were identified by relevant historical documents, testimony from witnesses and petitioners, records from the Uljin police station, and field research conducted throughout Uljin.
Split into simpler sentences: The incident took place between September 26,1959, and the end of December 1959. The victims were identified by relevant historical documents, testimony from witnesses and petitioners, records from the Uljin police station, and field research conducted throughout Uljin.