1. Rudolph MB (1986) The Theory and Practice of Meditation. (2nd edn), Mercury Publishers, New Delhi, India.
2. Newton K, Chitra J (2012) The Art & Science of Meditation. Life Publication, Hyderabad, India.
3. Yatiswarananda S (1979) Meditation and Spiritual Life. (3rd edn), Sri Ramkrishna Ashram, Bangalore, India.
4. Satyananda SS (1974) Meditations from the Tantras. (2nd edn), Yoga Publications Trust, Munger, India
5. Michael RG, Carolyn M (1998) Acu-Yoga: Self Help Tehniques to Relieve Tension. (1st edn), Health & Hormany, Jain Publishing (P) Ltd, New Delhi, India.