https://lmgtfy.app/?q=multilevel+analysis

What books about that topic have you read already?

I like this one: https://b-ok.cc/book/731115/8705fd?dsource=recommend

An easy-to-read introduction to multilevel modeling that I like a lot is

https://us.sagepub.com/en-us/nam/multilevel-modeling/book243884

When you type "multilevel analysis" or "multilevel modeling" into Google and/or Google Scholar, you can also find a lot of free resources/readings.

Thank you, Jochen Wilhelm and Christian Geiser, for your answers!

It is a good question, any one have more information don't or references does not skimp on us

Have a look at; all of this is free

http://www.bristol.ac.uk/cmm/software/mlwin/mlwin-resources.html#mlmbkgrd

and

http://www.bristol.ac.uk/cmm/learning/online-course/