TY  - BOOK
T1  - An operational necessity
A1  - Griffin, Gwyn
LA  - English
PP  - London
PB  - Collins
YR  - 1967
UL  - https://ds.mainlib.upd.edu.ph/Record/UP-99796217601577863
OP  - 411
CN  - PR 6013 R733 O64
KW  - World War, 1939-1945 : Naval operations : Submarine : Fiction.
KW  - Sea stories.
KW  - War stories.
ER  -