Welcome to 2021! The theme for this month is Recovery! The book I mention in the video (talking about Pawanmuktasana*) is called Asana, Pranayama, Mudra, Bandha by Satyananda Saraswati.
*meaning wind relieving asanas (wind as in gas and also energy, prana – moving the prana through the body). Strongly recommend reading this book and practicing the pawanmuktasana exercises daily.
Love, Peace, Joy