The phrase "a source of additional" is correct and usable in written English.
It can be used when referring to something that provides extra resources, information, or support in a particular context.
Example: "The new funding will serve as a source of additional support for our community programs."
Alternatives: "an extra source of" or "a means of extra".
In addition, our own archives were used as a source of additional information.
She landed both jobs, and hopes that they will be a source of additional contacts and leads.
Doctors and hospitals are eager customers of the latest machines as they increasingly turn to diagnostic tests as a source of additional revenue.
Housing equity withdrawal has added at least 5% to consumer spending in the past four years and is no longer available as a source of additional spending.
Chu and a number of other researchers are agreed that the production of corn-based ethanol is, on balance, a source of additional greenhouse gases.
The authority had appealed, arguing in part that the billboards were not only a source of additional revenue but also an aid to commuters.
CSUN officials cite the project, a public-private partnership dubbed the University MarketCenter, as a lucrative source of additional revenue and a convenient opportunity for student employment and internships.
For a country such as Morocco, remittances from international migrants constitute a major source of additional income for their families and a reliable source of foreign currency.
For the recording industry and performers, licensing songs provides a welcome source of additional revenue and publicity at a time when sales of recorded music continue to fall.
Late fees are a lucrative source of additional income for Blockbuster Inc., which is a unit of Viacom Inc., and its competitors.
"DomainPark represents a significant source of additional revenue for speculators," said Benjamin Edelman, an Internet researcher based in Cambridge, Mass.
