- - Manufacturers Literature Ferranti data book 1956
Babani, International Radio Tube Encyclopaedia P. 142 & 143
History of the British Radio Valve to 1940
Universal Vade-Mecum, Electron Valves and Semiconductor Devices
SPT2: Fin Stewart
Fin Stewart
Just Qvigstad
SPT2: My schematic collection.
Pier Antonio Aluffi