Complex sentence: Croatian wartime documents discovered in the Military History Institute in Belgrade after his death show that the ZNDH credited him with 44 confirmed kills, although at least one other source indicates a tally of 40 confirmed kills with five unconfirmed.
Split into simpler sentences: Croatian wartime documents discovered in the Military History Institute in Belgrade after his death show that the ZNDH credited him with 44 confirmed kills. At least one other source indicates a tally of 40 confirmed kills with five unconfirmed.