Spitz has collected the works of several important people in the reformation such as Luther, Calvin, and others. I find this information to be important to have on your shelf for reference, especially if you are a member of a protestant faith. The pieces are kept in their original words for the most part and so (because of the time difference) can be difficult to get through. It's short and worth the read. It contains Luther's 95 Theses and some prominent writings of John Calvin.

It helped me on the work I had to do