Сидоний Аполлинарий
They are mentioned as "Petrocoriis" by Caesar (mid-1st c. BC), "Petrokórioi" (Πετροκόριοι) by Strabo (early 1st c. AD) and Ptolemy (2nd c. AD), "Petrocori" by Pliny (1st c. AD), and as "Petrogorii" by Sidonius Apollinaris (5th c. AD).