She looked for the source and couldn't quite believe it.

He started to type, looking for the source of the problem.

Only the eye moved, looking for the source of the sound.

She reached for the source with her mind and eyes.

I have to wait for my source to contact me.

"I sent him looking for the source of the problem, but he came up with you!"

An example for a current source is shown in the figure on the right.

Then they want to use you for a source on a term paper.

He would have to search for the source of it in a moment.

My first choice for the source of this problem was water conditions.