Fantasy/Scifi/YA books from authors with certain letters

[Unsettledink]

Hello!

I'm doing a challenge to read a book from an author for every letter of the alphabet, but I wanted to make it a little more challenging for myself by only using books from authors I have not read before. I've managed to find almost every letter from my formidable tbr pile, but I'm missing a few letters and having trouble finding ways to search for them. I'm primarily looking for pretty much anything in the fantasy, scifi, or ya genres.

The letters I need (last name starting with) are q, u, x, and y.