TY  - BOOK
AU  - Ferris,John Robert
TI  - Behind the enigma: the authorised history of GCHQ, Britain's secret cyber-intelligence agency 
SN  - 9781526605481
AV  - HC445 .F345 2021
PY  - 2021///
CY  - UK; London
PB  - Bloomsbury Publishing
KW  - Great Britain
KW  - Government Communications Headquarters
KW  - Espionage
KW  - History
KW  - 20th century
N1  - Includes maps in endpapers and portrait on cover; Includes bibliographical references in endnotes and index
ER  -