WAIT!! I can't say for sure, but I believe I got infected from this site this morning. So until I know with certainty, DO NOT go to the site and certainly DON'T click on any of it's links. My virus check ran shortly after I visited there very early this morning, and found a Trojan Horse. YIKES!!!
This is not a book, but a site on WWII books that I found this morning while searching for something else. Love when that happens. 
Anyway when I clicked a search link it took me to this page:
https://vault2.secured-url.com/worldwarbook...ay=registration
Take a look at it. You can place check marks next to units/topics that are of interest to you and be alerted through email about those interests. That's pretty cool.
Oh, here's their main page:
https://vault2.secured-url.com/worldwarbook...sp?display=home