Moderate to advanced books?

I would love to hear some of your recommendations on books that you felt really helped you gain a more advanced understanding of investing. Ive been actively investing for a few years now and am comfortable with the fundamentals of the stock market and how markets function in general, but I feel like I’m missing something. I’d like to gain a more in depth grasp on investing strategies and reach that “next level.” In our current market, I’m finding it difficult to make solid gains. It feels to me