Marinus Komst was the former principal trumpet of the Concertgebouw Orchestra and was a prolific composer of trumpet etudes. His writing is modern, extremely technical, and as challenging as it is rewarding.
This book of Characteristic studies is probably the most approachable of the three etude books. They are melodic and interesting, while throwing more than a few technical/virtuosic flourishes your way. You are going to love working your way through these!
I have included the first study in the samples so you can give it a try, then grab an immediate PDF download above. Enjoy!