Further Reading recommendations:

Yoga Nidra - The Art of Transformational Sleep by Kamini Desai, PhD

The iRest Program for Healing PTSD - a Proven-Effective Approach to Using Yoga Nidra Meditation & Deep Relaxatopm Techniques to Overcome Trauma by Richard C. Miller, PhD

Clinical studies:

Clinical studies show that Yoga Nidra is associated with positive physiological changes. Find examples of this research here: (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9033521/ )

and also at: sleepfoundation.org