Roller, Duane W. (2006). Through the Pillars of Herakles: Greco-Roman Exploration of the Atlantic. Taylor and Francis, "Roman Exploration", p. 119. ISBN 0-415-37287-9. Geraadpleegd op 8 december 2008 "Footnote 28. Strabo 7.1.3. The name North Sea – more properly 'Northern Ocean', Septentrionalis Oceanus – probably came into use at this time; the earliest extant citation is Pliny, Natural History 2.167, 4.109."