Kriya Yoga is described by those practicing this style as an ancient yogic system ressicitated in modern times. It was internationally popularised by the book The Autobiography of a Yogi (Yogi Kathaamrt : Ek Yogi Ki Atmakatha) by Paramhansa Yogananda. This book introduced the practice of yoga to the West in the 1920s. This type of yoga is a sequence of dynamic and meditative asanas that include subtils aspects of yoga such as mantras, mudras and bandhas.