A CGDCT and Educational series worth adding to your list.
In honor of Girls & Panzer TV & OVA receiving a 5.1ch Blu-ray Disc BOX set, a new Akiyama Yukari's Tank Course "Extra" was made with nearly a half hour worth of content. A short ~7 minute watermarked 'preview' version was available on Bandai Namco's official YouTube Channel on September 29, 2018.
Plot summary from MyAnimeList. Data and images via Jikan API.