AbboFlury, De ratione spere, 170–185. Ed. by ThomsonRon B., “Two astronomical tractates of Abbo of Fleury”, pp. 113–33 in NorthJ. D.RocheJ. J. (eds), The light of nature (Dordrecht, 1985). It may be significant that Abbo's calculated position places Mars in the same constellation as do modern calculations.
