The phrase "are extremely restricted in" is correct and usable in written English.
You can use it to describe a situation where there are significant limitations or constraints in a particular area or context.
Example: "The researchers found that their options for experimentation are extremely restricted in this facility due to safety regulations."
Alternatives: "are highly limited in" or "are severely constrained in".
Although this simple approach has provided relatively good estimates of measured pile group behavior [5, 27], p-multipliers are extremely restricted in their application.
Moreover, sending down more National Guard troops who are extremely restricted in what they can legally do with regard to enforcement will likely have a marginal, if any, actual impact on border crossings, which are already at a record low, experts I spoke to said.
> We emphasize, however, that benchmarking results such as these should be taken with a grain of salt; both the BRAliBASE II and MASTR benchmarking sets are extremely restricted in their coverage of the space of RNA families, choosing to focus on a few individual RNA families only.
Abortion is extremely restricted in Northern Ireland, available only in private clinics.
In particular, molecular mobility is extremely restricted in the noncrystalline phase for the solvent-free sample, compared with the case of the gels.
"I would be extremely restricted in who I was and wanted to be in the future, including what I could say about Stieg and me in my life".
The short dispersal distances for all four species suggest that gene flow even within the natural landscape may be limited (for lizards, we did find a few significant FST values between sampling sites within continuous habitat), and therefore may be extremely restricted in a fragmented landscape.
If you're in insurance, it recently has gotten somewhat better, but for a long time, it's been extremely restricted, with rules very much in favor of Chinese companies, especially for opening new branches around the country.
Mountaineering in Bhutan is extremely restricted, apparently due to a combination of environmental concerns and respect for local spiritual beliefs.
