The phrase "a mainstream source" is correct and usable in written English.
It can be used to refer to a widely recognized and accepted source of information, such as news outlets, academic publications, or popular media.
Example: "The article was published in a mainstream source, which adds credibility to the claims made within it."
Alternatives: "a widely accepted source" or "a popular source".
"It does seem very odd that it has taken this long for a mainstream source to publish the fact".
As such, social finance is fast becoming a mainstream source of funding for goods and services that target the global poor.
But the network's fight for acceptance as a mainstream source of news may be hindered by the very positioning Mr. Murdoch has championed.
Despite such promise, however, it could take decades for thin films to transform solar power from a marginalized technology to a mainstream source of energy.
PoliticsDaily hopes to be a mainstream source of analysis and news and shuns the idea of being a news aggregator.
And what happens when the tool becomes so all consuming of people's attention and so capable of pushing individual buttons it becomes a mainstream source of public opinion?
At 8 p.m., Chocolate Factory, 5-49 49th Avenue, Long Island City, Queens, (212) 352-3101, chocolatefactorytheater.org; $15. (Burke Sally Silverss (Wednesday through Dec. 1) An experimentalist who's been embracing the awkward for decades, Ms. Silvers turns to a more mainstream source of inspiration — the musicals of Stephen Sondheim — in "Bonobo Milkshake," her first large ensemble work since 2009.
"If MSNBC wants to be seen as a trusted mainstream source of news and commentary, it needs to end its silence and fire Pat Buchanan".
Wind power, recently described by USA Today as "a decidedly mainstream source of energy," provided 10.6% of the electricity Texas required in 2014 and could provide nearly twice as much in a few years, according to Yale Environment 360's contributor Roger Real Drouin.
Fox News is an alleged "mainstream" source of news, yet 59% of their information is false.
Once a niche financial instrument, sukuk have become a mainstream alternative source of capital for corporations.
