@book{108316,
	author = {Whitney, Frederick, and Sargent, Walter,},
	title = {Blackboard Sketching},
	publisher = {Project Gutenberg,},
	year = {2022},
	address = {Salt Lake City, UT :},
	note = {Release date is 2022-02-25},
	url = {https://archive.org/details/blackboardsketch00whit/page/n5/mode/2up}
}