TY  - BOOK
AU  - Laird,Wilson Morrow
TI  - The upper Devonian and lower Mississippian of southwestern Pennsylvania
AV  - QE157 .A293 no. 126
PY  - 1941///]
CY  - [Harrisburg
KW  - Geology
KW  - Pennsylvania
KW  - Geology, Stratigraphic
KW  - Devonian
KW  - Mississippian
N1  - At head of title: ... Commonwealth of Pennsylvania.  Dept. of internal affairs ... Topographic and geologic survey; "Literature survey": p. 2-4
ER  -