While she was gone, he tried to find the source.

He was known for looking beyond the end result to find the source of the problem.

I looked around trying to find the source of the light.

However, I was not able to find the source of the data.

But on the other hand, we still haven't found the source.

It took little doing to find the source of the sound.

Yet it could not find the source of the light.

They would have to work fast to find the source.

It took him several more months to find the source.

Could take weeks to find a source for that much.