Sentence examples for been difficult to classify from inspiring English sources

Though some researchers have proposed a possible link between the Denisovans and human fossils from China that have previously been difficult to classify.

However, the pyramidelloids have always been difficult to classify.

It has been difficult to classify these proteins into different subfamilies for this reason.

The now nearly extinct Lipotes has been difficult to classify especially with respect to Inia and Pontoporia [ 12, 31].

Additionaly, the measures were used to assess possible phylogenetic relationships of T. maritima, which has been difficult to classify due to extensive horizontal transfer [ 20- 22].

To date, it has been difficult to classify unicellular and filamentous algae, especially diatoms and cyanobacteria, to the species level, especially in stomach contents, and evidence of dietary segregation in herbivorous cichlids in the same feeding ecomorph is scarce [ 4, 56].

In the traditional recognition approach, only one classifier is used; thus, it is difficult to classify all radar emitter signal samples.

Biographies are difficult to classify.

Basinski's music is difficult to classify.

Titled Love Remains, it was difficult to classify.

It's difficult to classify Dermansky's work.