The phrase "a relatively narrow group" is correct and usable in written English.
It can be used to describe a specific subset of people or things that are limited in scope or size compared to a broader category.
Example: "The study focused on a relatively narrow group of participants, specifically those aged 18 to 25."
Alternatives: "a somewhat limited group" or "a fairly small group".
One of the more striking aspects of the Great Recession is that most of its impact has fallen on a relatively narrow group of workers.
The main culprits are local governments and a relatively narrow group of companies: state-owned enterprises, property developers and construction firms.China's defences are now being tested by the prospect of the first big default in its property sector.
These matters, he said, will affect a "small group of people, 10 to 15 percent of Americans — now, it's still 30 million Americans, but a relatively narrow group — who don't have health insurance right now, or are on the individual market and are paying exorbitant amounts for coverage that isn't that great".
But the way I and others see it, the fee is more likely to be by paid by a relatively narrow group of individuals engaged in excessive borrowing at large institutions, while the benefits of taxing such risky behavior will redound broadly to the rest of us.
It also shows that large changes in selective driving forces are possible within a relatively narrow group of mammals, in this case a family of carnivorans.
It is an extracellular, glycosylated enzyme mainly found in a relatively narrow group of litter-decomposing fungi belonging to the Agaricaceae (Volc et al. 2001).
So all the implementation issues that are coming up are implementation issues related to that small group of people, 10 to 15 percent of Americans -- now, it's still 30 million Americans, but relatively narrow group -- who don't have health insurance right now or are on the individual market and are paying exorbitant amounts for coverage that isn't that great.
Building reference libraries of DNA barcodes is relatively straightforward when specifically designed primers are available to amplify the COI-5P region from a relatively narrow taxonomic group (e.g. single class or single order).
The patchy distribution of the CRISPR-Cas systems across the microbial diversity, and even within relatively narrow groups of bacteria [ 10, 42, 43], implies complex dynamics of virus-host coevolution.
Second, while WTP varied with financial means (results not shown) as might be expected, it did so within a relatively narrow range (75% of both wealthier and poorer groups would pay between USD 5 and USD 10).
Another drawback is that, being a natural number, it has low resolution, and a relatively narrow range so that it is common for a group of scientists to have an identical h-index.
