Babani, International Radio Tube Encyclopaedia p. 156 & 157
- - Manufacturers Literature
Universal Vade-Mecum, Electron Valves and Semiconductor Devices
Taschenbuch zum Röhren-Codex 1948/49
VP13S: Telefunken Werkstattbuch
Wolfgang Bauer
Just Qvigstad
VP13S: My schematic collection.
Pier Antonio Aluffi