APA (7th ed.) Citation

National Health and Environmental Effects Research Laboratory (U.S.) & Woods, A. J. (2006). Level III and IV ecoregions of Illinois. U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory.

Chicago Style (17th ed.) Citation

National Health and Environmental Effects Research Laboratory (U.S.) and Alan J. Woods. Level III and IV Ecoregions of Illinois. Corvallis, Or.: U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, 2006.

MLA (9th ed.) Citation

National Health and Environmental Effects Research Laboratory (U.S.) and Alan J. Woods. Level III and IV Ecoregions of Illinois. U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, 2006.