A great site for searching for new sheet music for any musical instrument is:

https://musescore.com/dashboard

You can search for a wide range of pieces completely free and there is an option for signing up for a relatively small annual fee that will open up even a wider selection of pieces to you. For me, this site has really been a life-saver! Without it, I would have been stuck many times looking for a specific music score or just generally searching for materials and musical inspiration.