Parker, J. (1864). “The Gentleman's Magazine”, The gentleman's magazine and historical review p.536216.
Martin, William. (1809) Petrificata Derbiensia p33-34. “p39 Fig 4....A fossil shell. The original a nautilus ... The crocodile said to be found in the limestone of Ashford, appears to be just a large specimen of this or some other Orthoceratite”.