Stover and Williams, 1989
From dinoflaj3
Stover, L.E. and Williams, G.L., 1989: Morphology and stratigraphy of the Paleogene dinoflagellate genera Areosphaeridium Eaton 1971 and Eatonicysta Stover and Evitt 1978. In: Fourth International Conference on Modern and Fossil Dinoflagellates, Woods Hole, April, 1989, Program and Abstracts, p. 95.