Interesting story regarding the use of a book merely written for development of high register. This would be funny if it wasn't so personal. A well known trumpet teacher around where I live wanted to develop his high register. (He had a solid high Eb). So he bought a book named "________" (can't remember but something like ___________). Did it work? Well, it depends on your amount of thirst for screaming out a few notes I guess. He played some ridiculously high notes and burst his ear drums! Moral of the story: take your time to develop your playing, there is no short cut. To this day, his high register is not too great (a few years ago I saw him he was trying a mouthpiece that will give him a high f. Of course it didn't work). To be fair, he is a fantastic player in other aspects and a great musician. When I heard him play the last variation of CoV I was quite impressed. I just could not find his approach to upper register "professional".