White fang’s original author, Jack London, has been dead for long enough now for his works to be in public domain, but translator of the specific edition is probably more important for common voice purposes, and I was not able to find that. Do you know the translator of the specific edition the sentences were taken from so you could check (you generally want him to be dead for more than 70 years for his work to fall into public domain)
Author of “Ironia Pozorow” is still alive as far as I was able to find, and I couldn’t find any information about him releasing the book into public domain - how it ended up on gutenberg in the first place is a slight mystery to me.
If it comes from Wikipedia, it needs to be gone.
Could you please re-check the Biały Kieł, and then post all of these into Sentence collector copyright issues for bookkeeping?