It uses no electricity nor other artificial sources of energy.

It was eventually named technetium due to its artificial source.

It comes from some artificial source down that tunnel.

The backlight can be a natural or artificial source of light.

This is the largest artificial source of radiation exposure for humans.

But the light there was as bright as artificial sources could make it.

The ceiling is made of domes with natural and artificial light sources.

He saw no overhead lamp or artificial light source anywhere else in the room.

Without the wall mirrors, the room became even gloomier, for there was no artificial source of light.

The only light came from the lightning and artificial sources.