TY  - BOOK
AU  - Marshall,R.B.
ED  - Illinois State Geological Survey
TI  - Results of spirit leveling in Illinois, 1909 and 1910
T2  - U.S. Geological survey. Bulletin 493
AV  - QE75 .B9 no. 493
PY  - 1911///
CY  - Washington
PB  - Govt. Print. Off.
KW  - Illinois
KW  - Altitudes
N1  - Includes index
ER  -