Cassandra Clare (2010). “Cassandra Clare: The Mortal Instrument Series (3 books): City of Bones; City of Ashes; City of Glass”, p.944, Simon and Schuster
Evelyn Underhill (2017). “The Complete Christian Mystic: A Practical, Step - By - Step Guide for Awakening to the Presence of God”, p.112, Lulu Press, Inc