Good morning to all: I would like some recommendation on reference books about the Pz iv D vs. the Pz iv J, or any books that give details about the differences between each variant. I'm also looking for book(s) on the Marder II that gives information on wheel dimensions, slope on the front upper hull,, side panels dimensions, track width, and the sort. I didn't sleep at a holiday inn last night, so I'm NO expert. Thanks for everyone's help.

Tim S