Author: Kyria d'Oreyn
Soran Milo was a writer who lived about six hundred years ago.
He met a peddler who had been to the Aiel Waste while he was writing a book called "The Killers of the Black Veil", presumably based on Aiel who came to a stedding in the Spine of the World. The peddler had remembered seeing a Portal Stone, and probably gave the information to Soran. This book is one of the sources that Rand uses when researching Portal Stones.
(Reference: The Shadow Rising, Chapter 22)