I’ve been using “Advanced Recorder Technique” by Heyens/Bowen, published by Schott. It’s a mouthful, so to speak, I’m not that advanced with it. Somewhat less daunting, but still very worthwhile is “95 Dexterity Exercises and Dances for Recorders in F” by G. Rooda.
Mostly alto, plays with Balmain Baroque