ASP.NET Custom Control – What is the best way to include embedded CSS reference only once?

The problem: I am embedding a CSS file into a custom control library with several controls. I want to share the same CSS file for all of the controls regardless of how many instances of them are on a given form. When more than one control is on the form, I would like exactly 1 reference to the CSS file in the HTML header of the ASP.NET page.

How to get ALL kinds of reverse package dependencies: reverse-depends pendant for non-Ubuntu distributions

I would like to find all possible reverse dependencies (no need for recursive reverse dependencies) of a certain package p, that is, I want to find all packages which depend on p. This shall include reverse dependencies on p‘s source package and also reverse build dependencies.