TY  - BOOK
AU  - Wilmarth,M.Grace
TI  - The geologic time classification of the United States Geological survey compared with other classifications, accompanied by the original definitions of era, period and epoch terms
T2  - U. S. Geological survey. Bulletin
AV  - QE75 .B9 no. 769
PY  - 1925///
CY  - Washington
PB  - Govt. print. off.
KW  - Geology, Stratigraphic
KW  - Geological time
N1  - Bibliographical references
ER  -