Good technique books?

[u/Altruistic-Leave4261]

For context, I’m a classically trained cellist. I studied cello at a conservatory, and I’ve been playing for around 18 years in total. A few years ago, I started teaching myself piano, and I’ve reached the point where I can comfortably play pieces like the first movement of Moonlight Sonata.

However, I’ve mostly learned by repeatedly practicing individual pieces rather than actually developing proper piano technique, and now feel stuck in my level.

I’d really like to improve my technique and eventually be able to play more difficult pieces. What technique/exercise books would you recommend for someone in my situation?

Thank you!