"Attempt to track the foreign programming back to its source," said Kirk.

That drug is too dangerous not to track it to its source.

"If I may, do you intend to continue tracking the signal to its source?"

She seemed bent on tracking the thunder in the earth to its source.

Julie wanted to see an expedition put together to track the things to their source.

So - the first thing to do would be to see if he and Robin could track the sermons to their source.

His eyes tracked the bright red line to its source.

We have to track this thing to its source and put a stop to it.

So it should be easy to track to its source.

"Haven't any of them tried to track the rumor to its source?"