TY  - BOOK
AU  - Petersen, Morris S.
AU  - Rigby, J. Keith.
TI  -  Interpreting earth history: a manual in historical geology 
SN  - 0697050637
U1  - 551.7  20
PY  - 1982///
CY  - Dubuque, IA
PB  - W.C. Brown
KW  - Historical geology
KW  -  Problems, exercises, etc
ER  -