The phrase "a significant class of" is correct and usable in written English.
It can be used when referring to a notable or important category or group within a larger context, often in academic or formal writing.
Example: "In the study of biodiversity, a significant class of organisms is the amphibians, which play crucial roles in their ecosystems."
Alternatives: "an important category of" or "a notable group of".
In this paper, for a significant class of uncertain MIMO systems, in particular for robots, new fundamental results are stated.
A significant class of deformations exhibits compressional rather than extensional features, and may be responding to localised glacio-isostatic rebound stresses.
A significant class of systems to which the control architecture can be applied is the class of linear systems with input saturation.
Such processes are sufficient for modelling a significant class of stochastic systems, however there are interesting systems which cannot be specified appropriately in such a framework.
Critics were soon complaining, however, that the program was too small and too fragmented to create a significant class of black business owners and that too many loans were being made to businesses that had little potential to grow.
If States, which comprise a significant class of owners and operators of hazardous-waste sites, see Brief for Respondent 8, need not pay for the costs of cleanup, the overall effect on voluntary cleanups will be substantial.
But that large class of cases also happens to be a very significant class of cases.
This would be another example of a small but significant class of public goods, participation in which is mandatory" [ 12].
To date, there are over 40,000 patents on DNA molecules [ 2, 3], including those on the breast and ovarian cancer genes BRCA1 and BRCA2 [ 4], indicating that patents on DNA are a widespread and significant class of intellectual property that have increased consistently since the 1980s.
Indeed, it is a typical representative of the clinically significant class of antibiotic-resistant opportunistic Enterobacteriaceae.
As a result, he further envisioned a vast array of interesting and significant classes of generalized convex functions.
