@book{106526,
	author = {Illinois State Geological Survey},
	title = {Guide to the Geologic Map of Illinois},
	publisher = {Project Gutenberg,},
	year = {2021},
	series = {Illinois State Geological Survey. Educational series, 7.},
	address = {Salt Lake City, UT :},
	note = {Release date is 2021-06-26},
	url = {https://www.gutenberg.org/ebooks/65704}
}