Interesting, any good reference on the web?

check the exercises on here (fast fwd to step 4 on the page): http://www.webmd.com/balance/stress-management/stress-management-breathing-exercises-for-relaxation these mostly train you to breathe deeper from your diaphragm and allow full air circulation and oxygenation

to me has a real result in making me calmer to be able to think clearly in moments of high anxiety