In this youtube clip at around 7:30 Maynard Ferguson talks about Atma Hathya's breathing techniques for when playing in the upper registers.
[ame=http://www.youtube.com/watch?v=G5ZStCND22U]YouTube - Maynard Ferguson Clinic: 05. Upper Register[/ame]
Any ideas on what he means? Recommended sights on the internet? Where to get copies of such books?