Can you give me a reference for some good examples? (S-L eigenvalue problem)?

Im trying to get a reference that goes through and shows all of the steps used to make a differential operator hermitian, and the solution to the eigenvalue problem etc.

its probably gonna be in an applied math text, or a physical mathematics text

or if there is just a good text on the subject, I would love to hear of one.

the text I got in college for the class that teaches this stuff (math. methods for theorical physics was the title) was mathematical methods in the physical sciences by Boas. It does not show the information I a looking for.