Armoured trains

(Sorry to be off subject, but) Can anybody recommend a good source (book or net) on armoured trains.
It´s a subject one would think animated nerds to compile info on, but I can´t find any good source.

There was a topic just made not too long ago, heres the link

http://www.ww2incolor.com/forum/showthread.php?t=6967

Thank you!

Guess someone can remove this now very redundant thread, so it wont take up space in here…