That was my only constant source of income the last two years.

It has been a constant source of difference between us.

And gas is the only constant source of fuel for the winter.

Beginning in the 16th century, this shared common land became a constant source of conflict.

My lower back and hips have become a constant source of concern over time.

The boy was a constant source of amazement to her.

He saw the need for a constant source of current.

That first kindergarten was a constant source of education to us.

It has been a constant source of concern ever since.

They make up and become a constant source of attention.