Can anyone recommend a decent alto trombone study method book with focus on trills and other ornaments?

I‘m particularly interested in how to get the best use out of an alto with Bb valve. This could include some exercises covering how to select the best partials to use, with or without valve, where mechanical trills may be considered etc.

Thanks in advance!

I touched on this subject in the study I wrote when I was 19, but I've done my best to erase that book from existence until I can find the time to finish a better version. 19 year old me wrote something to help himself learn the alto, and 34 year old me can do a lot better than that.

the basic concept is this:

Can you anyway do lip trills on the Bb tenor? If you can, then all of those trills are still open to you for use on the Bb valve on your alto. For example, Eb to F trill in a flat 3rd position with the valve engaged. Also, all of the trills on the open horn are available as well. With this alone, you can trill almost anything that you'll see in music. I didn't advocate a mechanical trill, except as an effect in the low Eb and Bb partials.

i believe adam woolf has a period performance book that will have a lot of info on trills and ornamentation. i don't believe it would have anything to do with valves though.

https://www.adamwoolf.com/store