- - Manufacturers Literature 1935
Babani, International Radio Tube Encyclopaedia P. 140 & 141
Universal Vade-Mecum, Electron Valves and Semiconductor Devices
Taschenbuch zum Röhren-Codex 1948/49
S215_Triotron: Fin Stewart
Fin Stewart
Just Qvigstad
S215_Triotron: own collection
Peter den Boer † 2025