I bought the Kindle version of Maximinus Thrax written by Paul Pearson, published by Pen and Sword books.
It is better than expected and give a good history about Maximinus Thrax a man of humble origin better finally being the emperor of the Romans Empire.
Short acounts of Septimus Severus, Caracalla and Elagabalus are given, Alexander Severus got more. Here is the chapter about the Persian campaign especially interesting.
The Harzhorn battle gets its own chapter.
Very interesting insights of the economic, religious and political life of the early century AD, shortly before the begin of the 3rd Century Crisis.