2016450th Anniv. Petri Nonii Salaciensis Opera - First Day Cover

The book Petri Nonii Salaciensis Opera – The Works by Pedro Nunes from Alcácer do Sal – was first published in 1566 in Basel and is the most significant scientific work written by Pedro Nunes (1502–1578). It constitutes the most important work by the most renowned and influential Portuguese mathematician of all time, and is thus a book that occupies a unique place in the history of science in Portugal.