1. Early Ordovician (Arenig) graptolites of the Cow Head Group, Western Newfoundland, Canada Author/Creator: Williams, S. Henry Publication/Creation: Calgary, Alta. : Canadian Society of Petroleum Geologists, 1988. St. John's, Nfld. : Geological Association of Canada, 1988 Resource Type: Book Access & Availability: Loading
2. Ediacaran-Ordovician of East Laurentia : S.W. Ford memorial volume Publication/Creation: Albany : New York State Museum, State Education Dept., 2007 Resource Type: Book Access & Availability: Loading