Iakovleva and Heilmann-Clausen, 2007
From dinoflaj3
Iakovleva, A.I. and Heilmann-Clausen, C., 2007: Wilsonidium pechorium new species -- a new dinoflagellate species with unusual asymmetry from the Paleocene/Eocene transition. Journal of Paleontology, v.81, no.5, p.1023-1033.