I ran into this issue when importing a library project (GreenDroid) and it turned out to be the @+id issue for me as well.
On this page you'll find documentation on the meaning of +. The page documents layout XML files, but the same applies to styles (yeah, they should put this information in a better place).
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.