TY  - BOOK
AU  - Tyrrell, G. W.
TI  -  The principles of petrology: an introduction to the science of r ocks 
SN  - 0412215004
U1  - 552 
PY  - 1926///
CY  - London
PB  - Chapman and Hall
KW  - Petrology
N1  - "Printed in Great Britain."; Includes bibliographical foot-notes
ER  -