APA (7th ed.) Citation

Geological Survey (U.S.) & Illinois. (1900). County map series (planimetric), [Illinois]. The Survey : Illinois Geological Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.) and Illinois. County Map Series (planimetric), [Illinois]. Reston, Va. : Champaign, Ill.: The Survey : Illinois Geological Survey, 1900.

MLA (9th ed.) Citation

Geological Survey (U.S.) and Illinois. County Map Series (planimetric), [Illinois]. The Survey : Illinois Geological Survey, 1900.