I found it in my parents book collection, it's a 3 volume set filled with personal accounts and after-action-reports written during WWI. My dad says the books are antiques and the books appear to have been published in either 1918 or 1919.

So I had questions for anyone who may know anything about these:
Are they really that old?
Is the information inside reliable?
Are these worth anything?

The books are pretty interesting, especially the stuff about the landings at Galipoli.