The Ordovician system in Canada : correlation chart and explanatory text/

by Barnes, Christopher R.
Ottawa : International Union of Geological Sciences, 1981

The ordovician system in Canada : correlation chart and explanatory notes /

by Barnes, Christopher R.
Ottawa, Ont. : Available from IUGS Secretariat, 1981

The Ordovician system in Canada : correlation chart and explanatory text /

by Barnes, Christopher R.
Ottawa : IUGS Secretariat, 1981

Illustrations of Canadian fossils : Cambrian, Ordovician and Silurian of the western Cordillera /

by Norford, B. S.
[Ottawa] : Dept. of Mines and Technical Surveys, 1962