Economic Geology of the Beaver Quadrangle, Pennsylvania: (southern Beaver and Northwestern Allegheny Counties)
Arthur Coe Spencer · Geological Survey (U.S.) · George Curtis Martin · Henry Gannett · Lester Hood Woolsey · Louis Caryl Graton · Ray Smith Bassler · Samuel Stinson Gannett · Charles Will Wright · David Henry Baldwin
Jan 1907 · U.S. Government Printing Office