A Global Historical GIS (GH-GIS) Project
Publication information:
John Gerring, Nathan Nunn, Robert Woodberry, Peter Bol, Wendy Guan, and Ben Lewis. 2009. “A Global Historical GIS (GH-GIS) Project”
Abstract
https://www.academia.edu/120228262/A_Global_Historical_GIS_GH_GIS_Project