I'm not an expert on the care of fruit trees, but can I suggest that you go to the following site and have a look at the instructions they give on 2 kinds of disease for the plum tree - ehow.com/how_7684720_treat-fungus-plum- This next site suggests that the black spot may be caused by a bacterial spot -Xanthomonas pruni. This site deals specifically with the disease - uri.edu/ce/factsheets/sheets/peachbact spot.html. Hope this is of some help.
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.