APA (7th ed.) Citation

Barnes, C. R., Norford, B. S., & Skevington, D. (1981). The Ordovician system in Canada: Correlation chart and explanatory notes. IUGS.

Chicago Style (17th ed.) Citation

Barnes, Christopher Richard, Brian S. Norford, and David Skevington. The Ordovician System in Canada: Correlation Chart and Explanatory Notes. Paris u.a: IUGS, 1981.

MLA (9th ed.) Citation

Barnes, Christopher Richard, et al. The Ordovician System in Canada: Correlation Chart and Explanatory Notes. IUGS, 1981.