Today I was looking for a book and found in a box these nice ones:
Some journals from 1937 - The Telefunken Vacuum-Tube

Rothe / Kleen - A standard in vacuum tube electronics
Book 1:
Pity, I do not own this one.
Book 2, 1943:

Book 3, 1944:

Book 4, 1940:

Book 5, 1941:

Fundamentals of Electron Devices from McGraw-Hill, 1962

Vacuum tubes and their circuits, 1962

And another standard book: Barkhausen - Textbook of Vacuum Tubes - General Fundamentals, Book one, 1962

Transmitter Tubes, 1951

And one of my favourite books ever: Meinke/Gundlach - High Frequency engineering pocketbook, 1962

Example: Antennas

Example: Vacuum tube made Flip-Flop

Hope I will find someday the book one from the Rothe / Kleen series to a reasonable price.