of Massilia, Pytheas. τά περί τοϋ Ώκεανοϋ (ta peri tou Hokeanou: On/About/Description of the Ocean). c 350/285 BC. {lost}:

Garlinghouse, Thomas S. ‘On the Ocean: The Famous Voyage of Pytheas’ at World History Encyclopedia (formerly Ancient History Encyclopedia), 14 July 2017.
https://www.worldhistory.org/article/1078/on-the-ocean-the-famous-voyage-ofpytheas/