Probably one of the best names ever for a computer game: Secret Weapons of the Luftwaffe (Lucasfilm Games, 1991)
What started with Battlehawks 1942 (1998) and Their Finest Hour (1989), found its conclusion in the last game of the World War II trilogy.
The manual (over 200 pages long) includes an in depth background of the Western European Air War between the years 1943 and 1945, technical specs for various planes, and air combat tactics. Secret Weapons of the Luftwaffe was definitely not for the casual gamer.