The Nachtjagd Combat Archive is possibly the largest WWII aviation project ever published running to over 1.3 million words with over 1200 original photos, a remarkable 70% of which are previously unpublished.
Good stuff Dominik.
I have the Luftwaffe Crash Archive and BoB Combat Archive series from the same publisher, and they're great. A bit pricey, getting the complete series, but worth every penny, and very well researched, presented and printed.