Harker and Sarjeant, 1990
From dinoflaj3
Harker, S.D. and Sarjeant, W.A.S., 1990: B. Taxonomy. In: Harker, S.D., Sarjeant, W.A.S. and Caldwell, W.G.E., Late Cretaceous (Campanian) organic-walled microplankton from the Interior Plains of Canada, Wyoming and Texas: biostratigraphy, palaeontology and palaeoenvironmental interpretation, Palaeontographica, Abteilung B, 219, p.27-153.