because when i try to assemble my models,
sometimes there is different selectable parts,
and i dont know what should i use.

for "example" , what i want is
"(with drawings,)this part name is blabla and it was fitted from november 1944"
and
"difference between ausf.h late and ausf.j early is
blablabla ...."
which book is best for panzer iv information like this?
panzertracts??