The phrase "a vast source" is correct and usable in written English.
It can be used to describe a large or extensive origin of information, resources, or materials.
Example: "The library serves as a vast source of knowledge for students and researchers alike."
Alternatives: "an extensive resource" or "a significant reservoir".
The second edition of Holinshed's Chronicles was at hand as a vast source for Shakespeare's historical playwriting.
British to its core, it is a vast source of all those half-forgotten rhymes for counting, patting, jiggling and soothing babies and toddlers.
He was prospecting for a vast source of clean, renewable energy that seemed straight out of a Jules Verne novel: the heat simmering within the earth's bedrock.
This number represents a vast source of untapped income – and in an era of declining retail sales for games, identifying new streams of digital revenue is becoming vitally important.
It doesn't help, Mr. Gurría said, that the United States, the world's second-largest energy consumer after China, has found a vast source of oil and natural gas in shale rock.
This exercise doesn't really need to have anything to do with social media, however, I do think that the internet is a vast source of information on careers, top professionals in each industry and the top jobs/employers in your field.
Enormous amounts of wastes generated from agricultural activities are a vast sources of plant nutrients, including macro- and micro-nutrients in organic forms.
Investors have been disappointed by the Monterey Shale, a potentially vast source of oil in the Golden State that has so far proved elusive and fallen below expectations.
Thus, a new and presumably vast source may be tapped for novel ligninolytic enzyme activities.
It's a question that's amplified to a worldwide scale when he's confronted by cameras, sees himself on television, and is recognized and hailed as a public hero while enduring spasms of self-questioning and self-doubt that are sparked by an external — and equally vast — source of doubt: the federal government.
The web's billions of pages provided a vast new source of fodder for the world's humming printers.
