Vierteljahrshefte für Zeitgeschichte online

[Halder]

I've been using the Vierteljahrshefte für Zeitgeschichte for over a decade; it's a first rate journal. Now the IfZ guys have digitised the first 30 years of it. Incredible!

http://www.ifz-muenchen.de/heftarchiv.html

There's an index on the home page which kindly lists articles by subject.

Unfortunately, the digitising project will stop in 1997; all the more recent volumes are available online but you have to pay. :-(

There's not loads on WW1, but there is some there. The index is very comprehensive and organised excellently.