It is known that for the classical orthogonal-polynomials there exist a set of Sturm Liouville problems. E.g. , the Hermite polynomial of order $n$ is a solution of $$y''(x) -xy'(x)+ny(x)=0 \, .$$

**My questions:**

- Given a finite measure $\mu$ on $\Omega \subseteq \mathbb{R}$, under what conditions does the respective set of orthogonal polynomials are a solution of respectve Sturm-Liouville problems?
- In these cases, can we go back from $\mu$ to the differential equations, rather then from $\mu$ to the polynomials?

Inasmuch as I collected from Szego's book on Orthogonal Polynomials and some talks around campus, the answer to (1) is only the classical polynomials, and to (2) is no. But I didn't find any evidence of it.

**EDIT - English Reference request:** I was referred in the comments to Bochner's "Über Sturm-Liouvillesche Polynomsysteme" for a complete answer. Can anyone refer me to a translation or a book-chapter that gives its own version, in English?

Thanks