Van Helden, 1977
From dinoflaj2
van Helden, B.G.T., 1977: Correlation of microplankton assemblages with ammonite faunas from the Jurassic Wilkie Point Formation, Prince Patrick Island, District of Franklin. Geological Survey of Canada, Paper, no.77-1B, p.163-171, pl.33.1-33.2.
