Harker, S. D.; Sarjeant, W. A. S.; Caldwell, W. G. E. (1990). Late Cretaceous (Campanian) organic-walled microplankton from the interior plains of Canada, Wyoming and Texas: biostratigraphy, palaeontology and palaeoenvironmental interpretation. Palaeontographica Abteilung B. 219 (1-6): 1-243.
97956
Harker, S. D.; Sarjeant, W. A. S.; Caldwell, W. G. E.
1990
Late Cretaceous (Campanian) organic-walled microplankton from the interior plains of Canada, Wyoming and Texas: biostratigraphy, palaeontology and palaeoenvironmental interpretation