The title says it all: Do you know a comprehensive (preferably online) reference about semi-direct products in (finite) group theory?
I would like to know much more about semi-direct products in the context of the classification of finite groups (of small order).
Thank you for your thoughts!
There is "algebra, abstract and concrete" by Robert M. Goodman.
It is free and as far as I know only available in PDF form sadly.
The chapter on group products (I assume that is what you mean).
Available here http://homepage.divms.uiowa.edu/~goodman/algebrabook.dir/algebrabook.html
If you require more advanced introduction I recommend Mark Steinberg's text titled "Algebra". The chapters 3 and 5 appear to consider classification if low order as well. Found here https://www.albany.edu/~mark/markbib.html