Perks, William, 1792 - "Youth's General Introduction to Guthrie's Geography...", London, 1792, Box: 2, Folder: 140. Research papers gathered for A Carto-Bibliography of the Maps in Eighteenth-Century English and American Geography Books, MS 287. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/234187 Accessed February 17, 2025.