Jacobson and Achab, 1985
From dinoflaj2
Jacobson, S.R. and Achab, A., 1985: Acritarch biostratigraphy of the Dicellograptus complanatus graptolite Zone from the Vaureal Formation (Ashgillian), Anticosti Island, Quebec, Canada. Palynology, v.9, p.165-198, pl.1-9.
