There is now a precise classification for the living members of the subfamily based on genetic research.

Its ancestry goes back 50 million years or more, and its precise classification is still a matter for argument.

There is no precise classification of casual genres in the modern gaming industry.

They may be less closely related to the tardigrades; precise classification is still in flux.

Although clear examples of the difference between cake and bread are easy to find, the precise classification has always been elusive.

Their precise classification would appear to be a matter for further research.

It is difficult to get a precise classification.

"A precise classification is not possible, as the molecule has never existed," Spock said.

Its precise classification remains the subject of spirited ongoing debate, whether "real" or not.

There is currently no agreement on their precise classification.