"In cooperation with the U.S. Bureau of Mines."Petroleum in Illinois 1917 and 1918, by N.O. Barrett.--Brown County, by Merle L. Nebel.--Goodhope and La Harpe Quadrangles, by Merle L. Nebel.--Parts of Pike and Adams Counties, by Horace Noble Coryell.--Experiments in water control in the Flat Rock Pool, Crawford County, by Fred H. Tough, Samuel H. Williston, and T.E. Savage
