The phrase "a substantial source for" is correct and usable in written English.
It can be used when referring to a significant origin or reference point for information, data, or resources in various contexts, such as academic writing or research.
Example: "The study serves as a substantial source for understanding the effects of climate change on marine life."
Alternatives: "a significant resource for" or "a major reference for".
Health-care workers are at a higher risk of infection than the general population and, in turn, may be a substantial source for susceptible individuals.
However, it is not yet known whether viable organisms are shed in quantities sufficient to constitute a substantial source for transmission.
Lesion assessment by ultrasound is based on the ACR BI-RADS®-US classification system that provides a substantial source for the prediction of the malignant or benign aspects of a tumor.
The effect of adiposity per se has not been studied, but it could be speculated that as a consequence of visceral fat accumulation there would be an increased flux of visceral fatty acids to the liver (35) that could provide a substantial source for VLDL-TG production and potentially liver fat deposition.
For its part, Columbia House, with annual revenue around $1.4 billion, has long been a substantial source of cash for Sony and Time Warner.
"Al-Jazeera's ability to influence public opinion throughout the region is a substantial source of leverage for Qatar," he wrote.
He went on: "Al-Jazeera's ability to influence public opinion throughout the region is a substantial source of leverage for Qatar, one which it is unlikely to relinquish.
"Overall, we were left with the impression that Skype and its related products and services could become a substantial source of revenue for eBay," though Rashtchy said that day could be far off given Skype's small revenue base.
Results of the scenario simulations show that temporally variable flow conditions can lead to significant temporal fluctuations of the concentration and thus are a substantial source of uncertainty for point measurements.
