Does a spectral theorem exist for linear operator pencils?

Question

I was wondering if a version of the spectral theorem (the projection valued measure case) holds for linear pencils of the form $$ A-\lambda B $$ where $A,B$ are self-adjoint on some Hilbert space $\mathcal{H}$ (and possibly unbounded) but $B$ is strictly positive? If so, is there a good reference on this? Note that under "nice" conditions, $B^{-1}A$ is self-adjoint on a weighted inner product (put factors $B^{1/2}$ in the inner product of $\mathcal{H}$ - this is straightforward to prove rigorously), so it may be the case that $B^{-1}A$ is usually studied instead.