TY  - BOOK
AU  - Petersen,Morris S.
AU  - Rigby J.Keith
TI  - Interpreting earth history: a manual in historical geology 
SN  - 0697050882
AV  - QE 28.3 .P48 1990
PY  - 1990///
CY  - Dubuque
PB  - W.C. Brown
KW  - Historical geology
KW  - Problems, exercises, etc
ER  -