This book, "Light on Prãnãyãma: The Yogic Art of Breathing," is a must-read for anyone interested in spirituality and yoga. It was written by B.K. Iyengar and B.K.S. Iyengar and published by Crossroad Publishing Company in 1985.

The book is a trade paperback and measures 8.2 inches in length, 5.4 inches in width, and 0.9 inches in height. It weighs 15.4 ounces and contains 320 pages. This book is perfect for those interested in learning more about yoga, pranayama, and spirituality.