Osprey Publishing is having a special offer till the end of September.
From their announcment:
Until the end of September we are offering you 25% off World War II titles across the Osprey website! A huge range of books are discounted on our World War II pages, including books that aren't even out yet – there's sure to be something to interest you! One of these titles is our greatly anticipated Hitler's Armies – a massive 400 page epic featuring some of the best artwork from our MAA series, that expertly weaves together the story of the development and deployment of Hitler's war machine.