Daniel J. Siegel (2015). “The Developing Mind, Second Edition: How Relationships and the Brain Interact to Shape Who We Are”, p.226, Guilford Publications
Diana Gabaldon (2015). “The Outlander Series 8-Book Bundle: Outlander, Dragonfly in Amber, Voyager, Drums of Autumn, The Fiery Cross, A Breath of Snow and Ashes, An Echo in the Bone, Written in My Own Heart's Blood”, p.20, Dell