TY  - BOOK
AU  - Gradstein, Felix M et, al..
TI  - Geologic time scale 2012
SN  - 9780444593900
U1  - 551.701 GRA 
PY  - 2012///
CY  - New York
PB  - Elsevier
KW  - Geologic time scale 2012
ER  -