Resources on the management of small teams, and people

Hello everyone

I am looking for resources on the management of small teams of engineers, or generally people. This could be, for example, a startup, or a unit in a established company (say, with max. 50 people). I would like to learn methods and best practices on the management of people in such setting.

I have background in research in tech, but no formal training in the management science or entrepreneurship (but I have some project management experience). I find myself progressively transitioning to managing R&D engineers.

I'm not in a situation to take a formal master's program or similar. I am thus looking for a resource that contains most of what is required in practice.

I wonder if people here have suggestions for, say, a good (text)book or online course?

I don't need books on self-help, motivation, or otherwise generics, rather, a proper, preferably academic, standard resource. I appreciate general advise and suggestions on management as well.

Thank you!