An objective that's common to both capitalism and socialism (and thus mixed economies) is production. Both systems rely on the production of goods and services (except that in capitalism one produces for profit and in socialism one produces for use--i.e. one produces according to human needs, not wants).
There are several primary sources that you might use, here are a few examples:
A diary written by a soldier during a battle.
Medical records of war doctors from the battle.
newspaper clippings about the battle (and published at the time of the battle).
Speeches of famous generals from the battle.
Faster moving object has speed
They treated hem with care and respect.
