Guide to the Geologic Map of Illinois, by anonymous anonymous 65704 [Subtitle: Educational Series 7] [Link: https://www.gutenberg.org/6/5/7/0/65704 ] [Files: 65704-0.txt; 65704-h.htm]
Thanks to Stephen Hutcheson and the Online Distributed Proofreading Team at https://www.pgdp.net Regards, Al
