TY  - BOOK
AU  - Spencer, Edgar^b.
TI  - Introduction to the structure of thr Earth / 
SN  - 07-085751-2
U1  - U2 
PY  - 1977///
CY  - New Delhi : 
PB  - MacGraw-HillKogakusha, Ltd , 
KW  - Geology
ER  -