Usage of Beta Binomial Distribution in Manufacturing - reference to JMP Help Info?

[#1]

In JMP help under Discrete Fit Distributions, the following is mentioned:

Beta Binomial

This distribution is useful when the data is a combination of several Binomial(p) distributions, each with a different p. One example is the overall number of defects combined from multiple manufacturing lines, when the mean number of defects (p) varies between the lines.

Does anyone has a reference, article, supporting this statement?

Kind regards

[#2]

On this page:

https://www.jmp.com/support/help/en/15.2/index.shtml#page/jmp/discrete-fit-distributions.shtml#ww116...

Agresti and Coull are referenced here.

Agresti, A., and Coull, B. A. (1998). “Approximate is Better Than ‘Exact’ for Interval Estimation of Binomial Proportions.” American Statistician 52:119–126.