Complex sentence: Between 1 July 1940 and 28 February 1941 Vale claimed 10 "Regia Aeronautica" aircraft in the Gladiator, although several of his victories are not confirmed.
Split into simpler sentences: Between 1 July 1940 and 28 February 1941 Vale claimed 10 "Regia Aeronautica" aircraft in the Gladiator. However, some of his victories are not confirmed.