David James Duncan (2002). “My Story as Told by Water: Confessions, Druidic Rants, Reflections, Bird-watchings, Fish-stalkings, Visions, Songs and Prayers Refracting Light, from Living Rivers, in the Age of the Industrial Dark”, p.88, Univ of California Press
Philip Gilbert Hamerton (1882). “The Sylvan Year: Leaves from the Note Book of Roaul Dubois. [Also The Unknown River. An Etcher's Voyage of Discovery]”