@book{26434,
	author = {Richardson, Charles Henry, and Hudnall, James S.,},
	title = {The mineralogy of Kentucky;},
	publisher = {The Kentucky geological survey,},
	year = {1925.},
	series = {Kentucky. Geological survey, 1920. Ser. VI.},
	address = {Frankfort,},
	note = {The Elkhorn coal field, by J. S. Hudnall: p. 131-133.}
}