Stevens and Helby, 1987
From dinoflaj3
Stevens, J. and Helby, R., 1987: Some Early Cretaceous dinoflagellates encountered in the Australian Kalyptea wisemaniae Zone. In: Jell, P.A. (editor), Studies in Australian Mesozoic palynology; Memoir of the Association of Australasian Palaeontologists, no.4, p.165-184.