Words similar to source

Example sentences for: source

How can you use “source” in a sentence? Here are some example sentences to help you improve your vocabulary:

This second source of calcium is not required for muscle contractions, but is required to sustain calcium-dependent signaling to the nucleus.
Both the WP and the New York Times cite one source each (the Post identifies him/her as "a source familiar with the session" and the NYT goes with "a Republican counsel at the interview) saying that yesterday Lewinsky said that Currie's pick-up of the gifts could have occurred later than she previously testified, and hence after the much-talked-about cell call Currie made to her.
But how, I asked Hatfield, could he see his source doing this in what he described as a telephone conversation?
Documentation needed, such as source code and manuals.
But where there is no evidence of borrowing and no feasible source language, some other explanation has to be sought.