Complex sentence: He entered the Military Industry School in Zemun in 1961, then went on to the KOV Military Academy, and then Officers Academy, graduating on 27 September 1965, starting his work in the Yugoslav Army.
Split into simpler sentences: He entered the Military Industry School in Zemun in 1961, and then went on to the KOV Military Academy, and then Officers Academy. Upon his graduating on 27 September 1965, he started his work in the Yugoslav Army.