Battleground Prussia: the Assault on Germany’s Eastern Front 1944-45 by Prit Buttar
This is a good account of the war in Prussia from late 1944 to the end of the war. It’s complementary to Christopher Duffy’s book in that it entirely focuses on Prussia and covers a slightly longer timeframe.
It has a lot of personal anecdotes that are interesting. It also covers the maritime evacuation along with the well known disasters.