Tocher and Jarvis, 1987
From dinoflaj3
Tocher, B.A. and Jarvis, I., 1987: Dinoflagellate cysts and stratigraphy of the Turonian (Upper Cretaceous) chalk near Beer, southeast Devon, England. In: Hart, M.B. (editor), Micropalaeontology of Carbonate Environments, p.138-175, pl.9.1-9.3; Ellis Horwood, Chichester, U.K.