Cassandra Clare (2011). “Cassandra Clare: The Mortal Instrument Series (4 books): City of Bones; City of Ashes; City of Glass; City of Fallen Angels”, p.566, Simon and Schuster
Chogyam Trungpa (2010). “The Collected Works of Chogyam Trungpa: Volume Three: Cutting Through Spiritual Materialism; The Myth of Freedom; The Heart of the Bud dha; Selected Writings”, p.244, Shambhala Publications
Roderick Impey Murchison (1854). “Siluria the History of the Oldest Known Rocks Containing Organic Remains, with a Brief Sketch of the Distribution of Gold Over the Earth by Roderick Impey Murchison”, p.5