"Blue Carbon: The Role of Healthy Oceans in Binding Carbon : a Rapid Response Assessment" by Christian Nellemann, Emily Corcoran, UNEP/Earthprint, (p. 23), 2009.
Henry Beston, Elizabeth Jane Coatsworth (2001). “The Best of Beston: A Selection from the Natural World of Henry Beston from Cape Cod to the St. Lawrence”, p.19, David R. Godine Publisher