causes — a person or thing that acts, happens, or exists in such a way that some specific thing happens as a result; the producer of an effect: You have been the cause of much anxiety. What was the cause of the accident?
sources — any thing or place from which something comes, arises, or is obtained; origin: Which foods are sources of calcium?
adjective cores
peripherals — pertaining to, situated in, or constituting the periphery: peripheral resistance on the outskirts of the battle area.
