TY  - BOOK
AU  - Walcott,Charles D.
TI  - Correlation papers ; Cambrian
T2  - U.S. Geological survey. Bulletin
AV  - QE75 .B9 no. 81
PY  - 1891///
CY  - Washington
PB  - Govt. Print. Off.
KW  - Geology, Stratigraphic
KW  - Cambrian
KW  - Geology
KW  - United States
N1  - Literature : p. 19-48
ER  -