De revolutionibus orbium coelestium
De libris revolutionum Copernici narratio prima, usually referred to as Narratio Prima (), is an abstract of Nicolaus Copernicus' heliocentric theory, written by Georg Joachim Rheticus in 1540. It is an introduction to Copernicus's major work, "De revolutionibus orbium coelestium", published in 1543, largely due to Rheticus's instigation. "Narratio Prima" is the first printed publication of Copernicus's theory.