Cassandra Clare (2010). “Cassandra Clare: The Mortal Instrument Series (3 books): City of Bones; City of Ashes; City of Glass”, p.186, Simon and Schuster
William Walker Atkinson (2016). “WILLIAM WALKER ATKINSON Ultimate Collection – 58 Books in One Volume: The Power of Concentration, The Key To Mental Power Development & Efficiency, Thought-Force in Business and Everyday Life, The Secret of Success, Mind Power, Raja Yoga, Self-Healing by Thought Force…”, p.6196, e-artnow