Internet, http://catalogue.bl.uk, 2006-07-26
Internet, http://darwin.lib.cam.ac.uk, 2006-07-27
The Nord-atlantic Sea-bed : comprising a diary of the Voyage on board H. M. S. Bulldog
in 1860 and observations on the presence of animal life, and the formation and nature
of organic deposits, at great depths in the ocean / by G. C. Wallich, 1862