TY  - BOOK
AU  - Twidale C R
TI  - Structural landforms:  Landforms associated with gr   
T2  - Introduction to system etic geomorphology ,5
U1  - U21, L1 
PY  - 1971///
CY  - Cambrdige
PB  - M I T Press       
KW  - Geomorphology
ER  -