Hi, I have corrected the German title. This special was in germany first released as DVD. The original DVD title is: "Dragonball Z Special: Die Geschichte von Trunks - Das Trunks Special"

Proof: https://www.amazon.de/-/en/Dragonball-Z/dp/B0000A2YD9

Please note: there is also another Special -> the Bardock special. This title is allready correctly on tmdb: https://www.themoviedb.org/movie/39323-z-z The Bardock special was in germany also released first as DVD. If you check pictures of the original DVD box, you will notice, that the Bardock Special is named in the same scheme: "Dragonball Z Special: Son-Gokus Vater - Das Bardock Special"

Proof: https://www.amazon.de/-/en/Dragonball-Z/dp/B00018WKJA/

So it makes sense to name booth titles in the same naming scheme and look in the names here. Thanks.