TY  - BOOK
AU  - Tyrrell,G.W.
TI  - The principles of petrology: an introduction to the science of rocks 
SN  - 8172250177
U1  - 552 22
PY  - 1926///
CY  - New delhi
PB  - B. L. publications PVT
KW  - Petrology
N1  - Includes index
ER  -