Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Ukrainian language:

"

Ukrainian verbs come in aspect pairs: perfective, and imperfective. Pairs are usually formed by a prepositional prefix and occasionally a root change. The past tense agrees with its subject in number and gender (but not person), having developed from the perfect participle.[citation needed]