The phrase "a rich source of material" is grammatically correct and can be used in written English.
It is typically used to describe something that provides a lot of information or material for a particular purpose. Example: The library's rare book collection was a rich source of material for my research paper on medieval history.
As with every other emotional event in his life, his troubles with women became a rich source of material.
Strong and Norman became close friends, and their letters to each other are a rich source of material, sometimes quite touching.
The philanthropists and former Met trustees Charlie and Jayne Wrightsman make for a rich source of material, including pages of Vanity Fair-worthy name-dropping and social climbing.
Proposed policies, including building a wall on the country's border with Mexico and temporarily banning Muslims from entering America, have provided comedians with a rich source of material.
In a course covering topics such as international economics or the challenges of penetrating emerging markets, for example, China is a rich source of material.
It's a curious stance, given that Davos's reputation as a sex Olympics for fatcats ought to make it a rich source of material for an award-nominated erotic novelist like Mason.
TEs comprise 47% of the genome of Aedes aegypti, a rich source of materials to search for active TEs.
Whole genome amplification (WGA) of bisulfite-modified DNA is expected to provide a rich source of materials, but its validity has not been thoroughly evaluated.
To Mr. Wilson -- a cheerfully voluble operative who worked for two former Republican governors, Christie Whitman and Donald DiFrancesco -- Mr. Corzine simply provides a richer source of material.
With its dense coils of steel, layers of fiber, and occasionally, wood, it is a rich source of reusable material.
A rich source of semiotic material is also to be found in the theologico-philosophical tradition.
