Quote Originally Posted by mah View Post
This site may be of interest-it also has a copyright search facility: Technical books online.

I believe this invaluable publication is free of copyright, at least in Australia: electron Tube Data sheets - RCA - Radiotron Designer's Handbook - 4th Edition - 1952

Some good winter reading.
Since Mah's RCA radiotron link is now busted, I'll put up this one: Radiotron Designer's Handbook - 4th Edition - 1952
And yeah, it is a classic reference.