Complex sentence: Karmen kept the reels though, as a result the only footages covering the battle are viewed from the Viet Minh side and his own work has been watched all around the world and even used in the western media.
Split into simpler sentences: Karmen kept the reels though, as a result the only footage covering the battle is from the Viet Minh's perspective. His own work has been watched all around the world and has even been used in the western media.