Most likely your static libraries use the same function (i.e. Deg2Rad) and you are getting this...
Try adding those to your project's target. Then clean and rebuild. I've had that problem as well sometimes and it was usually because I forgot those flags.
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.