Cita APA (7th ed.)

Geological Survey (U.S.) & Groschen, G. E. (2000). Water quality in the Lower Illinois River Basin, 1995-98. U.S. Geological Survey.

Cita Chicago (17th ed.)

Geological Survey (U.S.) i G. E. Groschen. Water Quality in the Lower Illinois River Basin, 1995-98. Reston, VA: U.S. Geological Survey, 2000.

Cita MLA (9th ed.)

Geological Survey (U.S.) i G. E. Groschen. Water Quality in the Lower Illinois River Basin, 1995-98. U.S. Geological Survey, 2000.