Light on Pranayama by BKS Iyengar
 
In this classic work, BKS Iyengar presents the definitive guide to pranayama, the yogic art of breathing.  Part  One presents the theory, art and techniques of pranayama, while Part Two offers insights into meditation and relaxation.
 
This authoritative and practical guide is an indispensable tool to the art and techniques of yogic breathing, for beginners and experienced yoga teachers alike.